The influence of chemical diluents on the antimicrobial activity of plant essential oil (EO) vapors was evaluated. We first determined if vapors generated from 22 chemical diluents not containing EO had antimicrobial activities. Ethyl ether vapor retarded the growth of S.
View Article and Find Full Text PDFAim: This study was done to determine the effects of temperature, pH and sodium chloride (NaCl) on antimicrobial activity of magnesium oxide (MgO) nanoparticles (NPs) against E. coli O157:H7.
Methods And Results: Culture conditions were established by varying the pH (5.
Aim: This study was done to develop a seed decontamination treatment for organic seeds against plant pathogens (Acidovorax citrulli and Xanthomonas campestris) using essential oil (EO) vapours without affecting the seeds' germination rate.
Methods And Results: By using a diffusion assay and determining minimum inhibitory and lethal concentrations, we screened two EO vapours which were most inhibitory to A. citrulli (cinnamon bark and garlic EO vapours) and X.
This study was done to develop a method to inactivate Escherichia coli O157:H7 on radish and cabbage seeds using simultaneous treatments with gaseous chlorine dioxide (ClO) and heat at high relative humidity (RH) without decreasing seeds' viability. Gaseous ClO was spontaneously vaporized from a solution containing hydrochloric acid (HCl, 1 N) and sodium chlorite (NaClO, 100,000 ppm). Using a sealed container (1.
View Article and Find Full Text PDFAbstract: Survival and growth of Salmonella and Shiga toxin-producing Escherichia coli (STEC) were investigated in kombucha prepared from four brands of commercially available kombucha kits intended for use by home brewers. Changes in populations of the indigenous microbiota responsible for fermentation of kombucha were also determined. An initial population of Salmonella (6.
View Article and Find Full Text PDFThis study investigated the antimicrobial activities of organic acid vapors against a phytopathogen (Acidovorax citrulli) and foodborne pathogens (Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes) on the surface of Cucurbitaceae seeds. Germination percentages of cucumber, honeydew melon and watermelon seeds treated with acetic and propionic acid vapors (100 mg/L) at 50 °C and 43% or 85% relative humidity (RH) for up to 2 h did not significantly (P > 0.05) decrease.
View Article and Find Full Text PDFThis study was done to identify combinations of essential oils (EOs) that elicit synergistic antimicrobial effects against Leuconostoc citreum, a spoilage bacterium in vegetable and fruit juices. Twenty-four EOs were tested for antimicrobial activity against L. citreum using an agar well diffusion assay.
View Article and Find Full Text PDFThe common use of gloves in retail practices represents a potential route for cross contamination of foodborne pathogens in fresh-cut produce. Using fresh-cut cantaloupe as a food model, we investigated factors that may influence glove-mediated cross contamination by Listeria monocytogenes and developed mathematical models to illustrate the patterns of transfer during fresh-cutting practices. Contact time (2, 5, 10 s), contact pressure (0.
View Article and Find Full Text PDFWe investigated combinations of gaseous essential oils (EO gases) for their synergistic inhibitory activities against Listeria monocytogenes on a laboratory medium and radish sprouts. The minimum inhibitory concentrations and minimum lethal concentrations of oregano, thyme thymol, and cinnamon bark EO gases against L. monocytogenes were 0.
View Article and Find Full Text PDFBackground: Acidovorax citrulli is a plant pathogen causing bacterial fruit blotch in Cucurbitaceae family. Applying high concentration of disinfectants to seeds containing plant pathogen may substantially decrease the germination rate of seeds. Therefore, it is necessary to develop a hurdle technology which can inactivate plant pathogens without decreasing seed viability.
View Article and Find Full Text PDFOf the 1648 microbial isolates from 133 soil samples collected from 30 diverse locations in the Republic of Korea, two isolates exhibited strong antilisterial activity and ability to grow to high populations (>8.0 log CFU/ml) in Bennett's broth. Isolates were identified as Streptomyces lactacystinicus (strain Samnamu 5-15) and Streptomyces purpureus (strain Chamnamu-sup 4-15).
View Article and Find Full Text PDFThis study was done to determine the antifungal activities of essential oil (EO) vapours of 97 plants against Penicillium corylophilum and to test combinations of EO vapours for synergistic antifungal effects. Among 97 commercially available EOs extracted from plant parts, garlic, cinnamon bark, may chang (mountain pepper), citronella, thyme thymol, oregano, spearmint, and thyme linalool EO vapours exhibited relatively strong antifungal activities. The minimal inhibitory concentrations of these EO vapours were 0.
View Article and Find Full Text PDFChili pepper (Capsicum annuum L.) powder and other powdered spices containing chili peppers are occasionally contaminated with foodborne pathogens. We applied chlorine dioxide (ClO) gas treatment to chili peppers prior to drying to inactivate Salmonella Typhimurium.
View Article and Find Full Text PDFLett Appl Microbiol
May 2018
Unlabelled: We produced a Pseudomonas veronii biofilm on the surface of a stainless steel that is inhibitory to Escherichia coli O157:H7. Pseudomonas veronii strain KACC 81051BP, isolated from lettuce, readily formed biofilm on the surface of stainless steel coupons (SSCs) immersed in tryptic soy broth at 25°C. Cells showed significantly (P ≤ 0·05) enhanced tolerance to desiccation stress (43% relative humidity (RH)) and retained antimicrobial activity against E.
View Article and Find Full Text PDFThe aim of this study was to evaluate the antimicrobial activities of gaseous essential oils (EO gases) against Listeria monocytogenes on the surfaces of a laboratory medium and radish sprouts. We determined the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) values of EO gases from eight EOs extracted from basil leaves, carrot seed, cinnamon bark, cinnamon leaves, clove flower buds, oregano leaves, thyme flowers (linalool), and thyme leaves (thymol) against L. monocytogenes on a nutrient agar supplemented with 1% glucose and 0.
View Article and Find Full Text PDFNon-pathogenic bacterial biofilms were developed on the surface of stainless steel possessing desiccation tolerance and antimicrobial activity against Salmonella enterica. Three bacteria exhibiting strong antimicrobial activities against S. enterica were isolated from various soils, foods, and food-contact surfaces.
View Article and Find Full Text PDFOutbreaks of salmonellosis have been associated with consumption of high-sugar, low-water activity (a) foods. The study reported here was focused on determining the effect of storage temperature (5 and 25°C) on survival of initially high and low levels of Salmonella in dry-inoculated sucrose (a 0.26 ± 0.
View Article and Find Full Text PDFThe aim of this study was to investigate the lethal effects of simultaneous treatments with gaseous chlorine dioxide (ClO) and mild wet heat (55 °C at 100% relative humidity [RH]) on Salmonella enterica in chicken feces on the surface of eggshells. Gaseous ClO production decreased significantly (P ≤ 0.05) as the RH (23, 43, 68, 85, and 100%) at 25 °C was increased.
View Article and Find Full Text PDFThe goal of this study was to develop a desiccation resistant antimicrobial surface using biofilm of competitive exclusion (CE) microorganism inhibitory to Staphylococcus aureus. We isolated 161 microorganisms from soils, foods, and food-contact surfaces that are inhibitory to S. aureus.
View Article and Find Full Text PDFSanitizing radish seeds intended for edible sprout production was achieved by applying simultaneous treatments with gaseous chlorine dioxide (ClO), high relative humidity (RH, 100%), and mild heat (55°C). Gaseous ClO was produced from aqueous ClO (0.66ml) by mixing sulfuric acid (5% w/v) with sodium chlorite (10 mg/mL) in a sealed container (1.
View Article and Find Full Text PDFFifty-six foods and food ingredients were analyzed for populations of naturally occurring yeasts and molds using Petrifilm rapid yeast and mold (RYM) count plates, Petrifilm yeast and mold (YM) count plates, dichloran rose bengal chloramphenicol (DRBC) agar plates, acidified potato dextrose agar (APDA) plates, and dichloran 18% glycerol (DG18) agar plates. Colonies were counted after incubating plates for 48, 72, and 120 h at 25°C. Of 56 foods in which either yeasts or molds were detected on at least one medium incubated for 120 h, neither yeasts nor molds were detected in 55.
View Article and Find Full Text PDFA study was done to determine the rate of inactivation of Salmonella in cookie and cracker snack sandwiches. Two cookie bases (chocolate and vanilla) and cheese crackers, along with high-sugar chocolate and peanut butter-based crème cookie fillings and peanut butter- and cheese-based cracker fillings, were obtained from commercial sources. Fillings and sandwiches containing fillings that had been dry- or wet-inoculated with Salmonella were stored at 25°C for 1, 6, 21, 35, 70, 112, and 182 days (6 months).
View Article and Find Full Text PDFThere is a growing interest in the use of naturally-occurring antimicrobial agents such as plant essential oils (EOs) to inhibit the growth of hazardous and spoilage microorganisms in foods. Gaseous EOs (EO gases) have many potential applications in the food industry, including use as antimicrobial agents in food packaging materials and sanitizing agents for foods and food-contact surfaces, and in food processing environments. Despite the potentially beneficial applications of EO gases, there is no standard method to evaluate their antimicrobial activities.
View Article and Find Full Text PDFThe synergistic effects of sequential treatments with chlorine dioxide (ClO2) and drying in killing Salmonella enterica on the surface of chicken eggshells were investigated. Initial experiments were focused on comparing lethalities of sodium hypochlorite (NaOCl) and ClO2. Eggs surface-inoculated with S.
View Article and Find Full Text PDFWe compared the microbiological quality of chicken eggshells obtained from a traditional wholesale market and a modern supermarket. We also determined the survival and growth characteristics of naturally occurring mesophilic aerobic bacteria (MAB) and artificially inoculated Salmonella enterica on eggshells under various environmental conditions (presence of chicken feces, temperature [4, 12, or 25 °C], and relative humidity [RH; 43 or 85%]). The populations of MAB, coliforms, and molds and yeasts on eggshells purchased from a traditional wholesale market were significantly (P ≤ 0.
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