Project description:Aims: To investigate the inactivation kinetics of Bacillus cereus vegetative cells upon exposure to low-temperature nitrogen gas plasma and to reveal the mode of inactivation by transcriptome profiling. Methods and results: Exponentially growing B. cereus cells were filtered and put on agar plates. The plates, carrying the filters with the vegetative cells, were placed into nitrogen gas plasma at atmospheric pressure and cold temperature (~37°C). After different exposure times the cells were harvested for RNA extraction and enumeration. The RNA was used to perform whole transcriptome profiling using DNA microarrays. The transcriptome profile showed a large overlap with profiles obtained from conditions generating reactive oxygen species inside B. cereus. However, excess radicals such as peroxynitrite, hydroxyl and or superoxide were not found. Conclusions: Antibacterial activity of nitrogen gas plasmas is not based on UV radiation but on the formation of reactive oxygen or nitrogen species in the plasma jet rather than inside the targeted cells. Significance and impact of the study: This study represents the first investigation of differential gene expression on a genome-wide scale in B. cereus following nitrogen gas plasma exposure. This study may help to design cheap, safe, and effective plasma decontamination devices.
Project description:Aims: To investigate the inactivation kinetics of Bacillus cereus vegetative cells upon exposure to low-temperature nitrogen gas plasma and to reveal the mode of inactivation by transcriptome profiling. Methods and results: Exponentially growing B. cereus cells were filtered and put on agar plates. The plates, carrying the filters with the vegetative cells, were placed into nitrogen gas plasma at atmospheric pressure and cold temperature (~37°C). After different exposure times the cells were harvested for RNA extraction and enumeration. The RNA was used to perform whole transcriptome profiling using DNA microarrays. The transcriptome profile showed a large overlap with profiles obtained from conditions generating reactive oxygen species inside B. cereus. However, excess radicals such as peroxynitrite, hydroxyl and or superoxide were not found. Conclusions: Antibacterial activity of nitrogen gas plasmas is not based on UV radiation but on the formation of reactive oxygen or nitrogen species in the plasma jet rather than inside the targeted cells. Significance and impact of the study: This study represents the first investigation of differential gene expression on a genome-wide scale in B. cereus following nitrogen gas plasma exposure. This study may help to design cheap, safe, and effective plasma decontamination devices. Plasma treated sampes compared with nitrogen gas flow treated samples and plasma treated samples compared to untreated control samples. Nitrogen flow samples in duplicate, plasma treated samples 4 replicates. Replicates hybridized with dyes swapped.
Project description:This project contributes to the proteomic comparison of the dynamics of emetic Bacillus cereus grown at low (16°C) and high (30°C) temperature.
Project description:This project contributes to the proteomic comparison of the dynamics of emetic Bacillus cereus grown at low (16°C) and high (30°C) temperature.
Project description:Interventions: experimental group:Orally take Combined Bifidobacterium, Lactobacillus, Enterococcus and Bacillus cereus Tablets;control group:Orally take placebo
Study Design: Parallel
Project description:The aim of the study was to carry out a CGH study utilizing a set of 39 diverse Bacillus isolates. Thirty four B. cereus and five B. anthracis strains and isolates were chosen so as to represent different lineages based on previous characterizations, including MLEE and MLST (Helgason, Okstad et al. 2000; Helgason, Tourasse et al. 2004). They represent the spectrum of B. cereus phenotypic diversity by including soil, dairy and periodontal isolates in addition to virulent B. anthracis strains.
Project description:Comparison of the Bacillus cereus with induced ComK1 (pATK31 in sample 1-3) or ComK2 (pATK32 in sample 4-6) proteins vs Bacillus cereus carrying empty plasmid (pLM5 in all samples)
Project description:Comparison of the Bacillus cereus with overexpressed Bacillus subtilis ComK (Bacillus cereus pNWcomKBsu) vs Bacillus cereus carrying empty plasmid (Bacillus cereus pNW33N) One condition design comparision of (IPTG induced overexpression construct vs IPTG induced empty plasmid) including a dye swap, 3 biological replicate
Project description:Pathogenic species belonging to Bacillus cereus sensu lato group possess a high evolutionary advantage in the environment and in food matrices thanks to their capacity to survive as silent spores to harsh environmental insults and grow at relatively low temperatures. Ready to re-heat products are at severe risk for contamination by members of Bacillus cereus s.l. group if not stored at proper conditions. In this work, the goal was to assess, by means of a genome-wide transcriptional assay, the isolated strain Bacillus cereus UC10070 gene expression behind the process of spore germination and consequent outgrowth in an artificially contaminated vegetable-based food model. A vegetable food model subjected to a heat treatment was determined to present favourable conditions for spores germination. Microscopic analyses together with OD measurements were applied to select the key steps of B. cereus cell cycle to be used for the microarray analysis. Using this approach we found a total of 1,646 probe sets differentially expressed and modulated during the entire B. cereus life cycle in the vegetable foodstuff.
