Understanding the ecology and virulence of Legionella spp. populations in freshwater systems in Germany, Palestine and Israel - Phase 2

• Applicant: Professor Dr. Manfred Höfle
• Co-Applicants: Professorin Dr. Dina M. Bitar; Dr. Malka Halpern
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management ; Microbial Ecology and Applied Microbiology
• Term: from 2011 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 202422244

Bacteria of the genus Legionella cause waterborne infections resulting in severe pneumonia. In Europe, 70% of the cases of the so-called Legionnaires’ disease (LD) originate from strains of L. pneumophila serogroup (Sg) 1, 20% from other L. pneumophila serotypes and 10% from other Legionella species. In contrast, in the Middle East most legionella infections are due to L. pneumophila Sg3. The overall objective of this project is to advance current knowledge on the ecology of legionella in freshwater systems, the environmental factors affecting their occurrence, virulence potential and infectivity and to understand their transmission to humans. We will analyze the major environmental factors regulating the abundance of legionella, such as grazing and assimable dissolved organic carbon, because the occurrence of these heterotrophic bacteria in aquatic habitats is highly dependent on these factors. We will use an integrated molecular approach based on highresolution diagnostics of environmental samples and clinical isolates to determine the abundance, activity and virulence potential of Legionella populations in-situ. Combining environmental and molecular epidemiological data, we aim at understanding the link between ecology and population dynamics of legionella and cases of LD. The project will result in a novel understanding of the molecular epidemiology of legionella and provide new surveillance tools and strategies to prevent LD.

• DFG Programme: Research Grants
• International Connection: Israel, Palestine