Project description:The EepR protein is a two-component response regulator protein in the bacterium Serratia marcescens. Mutation of the eepR gene results in pleiotropic changes including reduced expression of secondary metabolites and proteases.
Project description:In order to identify mRNA and sRNAs associated with the RNA-binding protein Hfq in Serratia marcescens strain Db10, Hfq-bound RNA was immunoprecipitated from a strain encoding an Hfq-3FLAG fusion protein at the normal location and sequenced, in parallel with the wild type strain (no fusion) as negative control. Additionally global transcriptional start site mapping was performed on total RNA, with or without TEX treatment, isolated from wild type Serratia marcescens. The data was used to identify regions of mRNA and sRNAs associated with Hfq in this organism. Associated work in Serratia marcescens Db10, an opportunistic bacterial pathogen, has shown that Hfq is essential for virulence in several models and exerts a wide-ranging impact on the transcriptome and, particularly, genes encoding virulence factors.
Project description:The GumB protein is an IgaA-family member that negatively regulates the Rcs stress response system in the bacterium Serratia marcescens. Mutation of the gumB gene results in increased RCs system activity of numerous genes including those involved in flagellar based motility and capsular polysaccharide formation.
Project description:In order to identify changes in the global mRNA transcriptome caused by deletion of the RNA-binding protein Hfq in Serratia marcescens, total mRNA was isolated from wild type Serratia marcescens Db10 and an otherwise isogenic strain carrying an in-frame deletion of the hfq gene (SMDB11_4482) and analysed by RNAseq. Four independent biological replicates were sequenced for each strain using the Illumina HiSeq platform. The data was used to identify the nature and extent of changes in transcript level between the two strains and to inform on the role of Hfq in virulence of Serratia marcescens, an opportunist bacterial pathogen.
Project description:Screening a library of 573 cyanobacteria extracts for inhibition of the quorum sensing regulated prodigiosin production of Serratia marcescens, an extract of the cyanobacterium Fischerella ambigua (Näg.) Gomont 108b was found to drastically increase the prodigiosin production. Bioactivity-guided isolation of the active compounds resulted in the two new natural products ambigol D and E along with the known ambigols A and C. Ambigol C treatment increased prodiginine production of Serratia sp. ATCC 39006 (S39006) by a factor of 10, while ambigols A and D were found to have antibiotic activity against this strain. RNA-Seq of S39006 treated with ambigol C and subsequent differential gene expression and functional enrichment analyses indicated a significant downregulation of genes associated with the translation machinery and fatty acid biosynthesis in Serratia, as well as increased expression of genes related to the uptake of l-proline. These results suggest that the ambigols increase the prodiginine production in S39006 not by activating the SmaIR quorum sensing system, but possibly by increasing the precursor supply of l-proline and malonyl-CoA.
Project description:Drosophila melanogaster oral infection by the entomopathogen bacteria Serratia marcescens trigger, at the midgut level, a drastic phenotype during the early phase of the exposure. In response to Serratia marcescens virulence factors the enterocytes present a rapid formation of megamitochondria and a subsequent controlled extrusion of the cytoplasm along with damaged organelles, which may constitute a repair mechanism. This results in a thin intestinal epithelium that then recovers its original shape in just a few hours. In order to identify, at the midgut level, the transcriptional modifications induced by Serratia marcescens during this early phase of the infection, we performed a RNAseq transcriptomics analysis of the flies intestine three hours after bacteria ingestion. We found that 144 genes were significantly induced and that 34 genes were repressed at this time point in comparison to the non infected midguts.
