Gonococcal secretome during the transition from single cells to microcolonies

• Applicant: Dr. Stephan Wimmi
• Subject Area: Medical Microbiology and Mycology, Hygiene, Molecular Infection Biology ; Metabolism, Biochemistry and Genetics of Microorganisms
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 545504326

Neisseria gonorrhoeae is an exclusively human pathogen and today, one of the most common sexually transmitted diseases. In a single cell state, it moves via type 4 pili (T4P). With elevated cell densities, T4P interactions between different cells result in cell aggregation and the formation of spherical microcolonies. Through colony fusion and growth, these develop into a full-grown biofilm. To export proteins, facilitate host interaction and adhesion or to shape their environment, N. gonorrhoeae use a number of dedicated secretion systems (Type 1-, Type 4-, Type 5 secretion system). With this project, I want to systematically investigate the secretome and secretion systems of N. gonorrhoeae and unravel the spatial and temporal regulation during the transition from single cells to biofilms. I will create a secretion system deletion library and systematically investigate the effects of these deletions on growth, microcolony formation and secretome. Comparison of the secretome in purely planktonic and microcolony-forming strains will allow me to identify the aggregation-related secretome. To investigate whether the process of secretion is synchronized or heterogenic within the population, I will create fluorescent reporters that allow me to follow the gene expression of the respective secretion systems. This will enable me to investigate the expression pattern of the chosen system in the planktonic and microcolony cell state and give me a resolution in which I can determine differential gene expression of single cells with respect to their spatial and temporal position within the microcolony. In conclusion, this project will allow me to reveal how different secretion systems of N. gonorrhoeae contribute to and are utilized during the transition from single cells to microcolonies.

• DFG Programme: WBP Position