Antibiotic persistence: Analysis of mucosal cells harboring relapse-relevant S. Typhimurium persisters

• Applicant: Tom Völler
• Subject Area: Parasitology and Biology of Tropical Infectious Disease Pathogens
• Term: from 2016 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 321202858

Antibiotics are a cornerstone of modern medicine. However, bacteria often survive antibiotic treatment. Two different mechanisms are thought to be responsible, phenotypic persistence and genetic resistance. While resistance has been studied extensively, much less is known about phenotypic intracellular persistence. Persistence is a gene expression program that is still not completely understood. Nonetheless, it leads to bacterial survival of antibiotic treatment and, thereby, causes relapses without the need for genetic alterations.The proposed project is designed to identify persister-lodging host cells in a mouse model for S. Typhimurium diarrhea and, in a second step, to determine their in vivo importance for relapse generation and therapeutic intervention. To achieve this goal, the project features the merge of static and dynamic methods in different genetic backgrounds and cell depletion models. Briefly, 3D fluorescence microscopy will be combined with FACS cell sorting to sharply identify persisting bacteria in infected host cells on a single cell level as well as in fixed tissue sections. FACS sorted persister-lodging cells will be plated to assess the viability of contained persisters.In the second step, the in vivo importance of identified persister-lodging cell types for relapses will be studied with knockout mice, cell depletion and cytokine stimulation. Relapse kinetics will be assessed via within host cell population dynamics. As a further readout, inflammation imaging will be used to study the dynamics of inflammation and its impact on persister formation. The data will advance our understanding of persister formation in vivo and provide an important starting point for the future development of improved therapies.

• DFG Programme: Research Fellowships
• International Connection: Switzerland
• Host: Professor Dr. Wolf-Dietrich Hardt