Regulation of biofilm formation and cellulose production in Salmonella enterica serovar Typhimurium

• Applicant: Dr. Annika Maria Cimdins-Ahne
• Subject Area: Parasitology and Biology of Tropical Infectious Disease Pathogens ; Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2014 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 271093957

The project aims at investigating differential gene expression in Salmonella biofilms and regulation of cellulose synthesis. The Karolinska Institute in Stockholm, Sweden will serve as foreign host institution. Research will be performed in the group of Prof. Dr. Ute Römling, Department of Microbiology, Tumor and Cell Biology. The project involves a differential RNA sequencing approach, which will be performed in collaboration at the Institute for Molecular Infection Biology, Würzburg (Prof. Dr. Jörg Vogel).Salmonella typhimurium can form biofilms, multicellular structures with increased stress resistance. The main transcriptional regulator in biofilms is CsgD. Interestingly, not all cells express csgD. This bistable expression pattern will be investigated under different conditions using a CsgD-GFP reporter strain. CsgD expressing and non-expressing cells will be separated by fluorescence activated cell sorting. RNA from both populations will be subjected to differential RNA sequencing. This global approach will reveal regulatory sRNAs involved in bistable expression in biofilms and give further insight into c-di-GMP dependent, CsgD mediated biofilm formation.One component of the extracellular matrix formed by Salmonella in biofilms is cellulose. Two operons are known to encode genes important for cellulose production. Chromosomal reporter fusions to different genes involved in cellulose biosynthesis will shed light on transcriptional and post-transcriptional regulation. To identify novel regulators, random transposon mutagenesis will be performed. Further, the importance of the RNA chaperone Hfq and small regulatory RNAs on biosynthesis of cellulose will be investigated.

• DFG Programme: Research Fellowships
• International Connection: Sweden
• Host: Professorin Dr. Ute Römling