Dataset Information

Susceptibility of Escherichia coli O157:H7 grown at low temperatures to the krypton-chlorine excilamp.

ABSTRACT: This study was conducted to investigate the resistance of Escherichia coli O157:H7 to 222-nm krypton-chlorine(KrCl) excilamp and 254-nm low-pressure Hg lamp (LP lamp) treatment according to growth temperature. As growth temperature decreased, lag time of E. coli O157:H7 significantly increased while the growth rate significantly decreased. Regardless of growth temperature, the KrCl excilamp showed higher disinfection capacity compared to the LP lamp at stationary growth phase. KrCl excilamp treatment showed significantly higher reduction as growth temperature decreased. Conversely, reduction levels according to growth temperature were not significantly different when the pathogen was subjected to LP lamp treatment. Inactivation mechanisms were evaluated by the thiobarbituric acid reactive substances (TBARS) assay and SYBR green assay, and we confirmed that lipid oxdiation capacity following KrCl excilamp treatment increased as growth temperature decreased, which was significantly higher than that of LP lamp treated samples regardless of growth temperature. DNA damage level was significantly higher for LP Hg lamp treated samples compared to those subjected to the KrCl excilamp, but no significant difference pursuant to growth temperature was observed. At the transcriptional level, gene expression related to several metabolic pathways was significantly higher for the pathogen grown at 15?°C compared that of 37?°C, enabling it to adapt and survive at low temperature, and membrane lipid composition became altered to ensure membrane fluidity. Consequently, resistance of E. coli O157:H7 to the KrCl excilamp decreased as growth temperature decreased because the ratio of unsaturated fatty acid composition increased at low growth temperature resulting in higher lipid oxidation levels. These results indicate that KrCl excilamp treatment should be determined carefully considering the growth temperature of E. coli O157:H7.

SUBMITTER: Lee JI

PROVIDER: S-EPMC6346039 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Susceptibility of Escherichia coli O157:H7 grown at low temperatures to the krypton-chlorine excilamp.

Lee Jae-Ik JI Kim Sang-Soon SS Kang Dong-Hyun DH

Scientific reports 20190124 1

This study was conducted to investigate the resistance of Escherichia coli O157:H7 to 222-nm krypton-chlorine(KrCl) excilamp and 254-nm low-pressure Hg lamp (LP lamp) treatment according to growth temperature. As growth temperature decreased, lag time of E. coli O157:H7 significantly increased while the growth rate significantly decreased. Regardless of growth temperature, the KrCl excilamp showed higher disinfection capacity compared to the LP lamp at stationary growth phase. KrCl excilamp trea ...[more]

PMID: 30679621

Similar Datasets

Project description:Treatments of wastewater and fresh produce commonly employ chlorine as an antimicrobial. However, there are increasing levels of concerns regarding the safety and antimicrobial efficacy of chlorine treatments. Numerous studies have reported the antimicrobial properties of chlorine dioxide (ClO2) treatment in a variety of applications but information regarding how ClO2 affects bacteria is limited. In the present study, a mixed-method approach utilizing both quantitative and qualitative methodologies was used to observe Escherichia coli O157:H7 membrane damage after exposure to ClO2 (2.5, 5, or 10 mg/L) for 5, 10, or 15 min. For comparison, controls of 0.1% peptone, 70% isopropanol, and 10 mg/L NaOCl were applied for 15 min. After treatment, cells were enumerated on selective media overlaid with non-selective media and simultaneously analyzed for damage using the following fluorescent probes (1) Bis-(1,3-Dibutylbarbituric Acid) trimethine oxonol (DiBAC4(3)) for membrane polarization, (2) SYTO 9/propidium iodide (LIVE/DEAD) for membrane permeability, (3) 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)Amino)-2-Deoxyglucose (2-NBDG) for active glucose uptake, and (4) lipid peroxidation through accumulation of malondialdehyde (MDA). Bacterial log reductions after ClO2 treatment ranged from 0.2 to 5.5 and changes in relative fluorescence units after membrane permeability and glucose uptake assays were not consistent with viability, indicating membrane permeability and metabolism were not substantially altered. Depolarization was observed after NaOCl treatment, however, the polarity of cells treated with ClO2 were like those treated with water (P < 0.05). Accumulation of MDA was detected only after 10 mg/L ClO2 treatments, indicating that membrane peroxidation occurred at higher concentrations. Transmission electron microscopy imaging revealed that separation of the cell wall from the cytosol occurred after the 10 mg/L ClO2 treatment, but the cell wall itself appeared to be unbroken. These data suggest that ClO2 damage to E. coli O157:H7 is not primarily located at the cell wall and harms cells significantly different than NaOCl at comparable concentrations.

Dataset Information

Susceptibility of Escherichia coli O157:H7 grown at low temperatures to the krypton-chlorine excilamp.

Publications

Susceptibility of Escherichia coli O157:H7 grown at low temperatures to the krypton-chlorine excilamp.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets