Project description:We isolated an atmospheric contaminant, subsequently identified as a new strain of Bacillus mobilis, which showed a novel, robust, inducible filamentous sliding motility and completely colonized a bacterial culture plate in less than 48 h under some conditions. This flagella-independent sliding motility was characterized by long filamentous cells at the expanding edge, and was induced when cells were inoculated onto lawns of metabolically inactive Campylobacter jejuni cells, heat killed bacterial biomass, and milk or blood dried onto agar plates. Phosphatidylcholine (PC), bacterial membrane components, and sterile human fecal extracts were sufficient to induce filamentous expansion. Screening of eight other Bacillus spp. (five from the B. cereus group and three other Bacillus spp.) showed that filamentous motility was conserved amongst B. cereus group species to varying degrees. RNAseq of filamentously expanding cells collected from PC and milk lawn plates in comparison to rod-shaped cells from control plates revealed that genes related to metabolism, ion and amino acid transport were differently regulated, genes controlling sporulation were reduced, and some virulence genes (e.g., hblA/B/C/D and plcR) were increased. We hypothesize that the robust and conserved nature of filamentous motility in pathogenic B. cereus group species can enhance bacterial colonization during host colonization.
Project description:The Bacillus cereus group consists of eight very closely related species and comprises both harmless and human pathogenic species. Yet, methods to rapidly and accurately distinguish these species are currently lacking as we demonstrate that classical matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) biotyping did not achieve reliable identification of each type strain. We assigned type strain-specific diagnostic peptides to the B. cereus group based on comparisons of their proteome profiles. The number of diagnostic peptides varies remarkably in type strain-dependent manner. The state of the art of the reference database is crucial in the process of validating candidate diagnostic peptides and may lead to a noteworthy reduction of verified diagnostic peptides as putative diagnostic peptides might be found in other species as well.
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.
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:Comparative Genomic Hybridization. Analysis of genomic content of closely related Bacillus species. Refer to individual records for strain information. Refer to platform and individual sample records for experimental protocols. Keywords: other
Project description:This SuperSeries is composed of the following subset Series: GSE13711: Comparative transcriptome and phenotype analysis of acid-stressed Bacillus cereus strain ATCC 14579 GSE13729: Comparative transcriptome and phenotype analysis of acid-stressed Bacillus cereus strain ATCC 10987 Refer to individual Series
Project description:This project provides tandem mass spectrometry datasets of Bacillus cereus ATCC 14579 wild-type strain without its pBClin15 plasmid. The strain was grown under fermentative anaerobic condition and harvested at three growth stages.
Project description:This project provides tandem mass spectrometry data of Bacillus cereus AH187 strain. The strain was grown on liquid MOD medium supplemented with glucose and harvested at three growth stages.
