Project description:Genomic DNA of 61 strains of proteolytic Clostridium botulinum or Clostridium sporogenes was subjected to analysis by DNA microarray.
Project description:The members of the genus Clostridium, such as the other spore-forming anaerobic bacteria, have a complex and strictly regulated life-cycle but very little is known about genetic pathways involved at different stages. Clostridium sporogenes, Gram positive bacterium usually involved in food spoilage and frequently isolated from late blowed cheese is genetically indistinguishable from proteolytic Clostridium botulinum and is the non-neurotoxigenic counterpart often used as exemplar for the toxic subtypes. In this work we have performed a microscopy study combined with a custom array-based analysis of C. sporogenes cycle, from dormant spores to early stationary phase. We identified in spores a total of 211 transcripts validating the ipothesis that mRNAs are abundant and strikingly different from those present in growing cells. The spores transcripts included genes responsible of different life-sustaining functions, suggesting the theory of transcripts entrapment or of a basic poly-functional genes activation for future steps. In addition, after three hours from the beginning of the germination process, a 20% of the total up-regulated genes were temporally expressed in germinating spores. The vegetative condition appears to be the more active in terms of gene transcription and protein synthesis and also genes for germination and sporulation factors seem to be expressed at this point. These results suggest that spores are not silent entities and a wider knowledge about genetic pathways involved in Clostridium life cycle could be of help for a better understanding also of pathogenic clostridia types.
