Virulence, communication, and persistence of Legionella

Legionella species are Gram-negative bacteria, which replicate in environmental amoeba and in lung macrophages, thereby triggering a severe pneumonia termed Legionnaires’ disease. The pathogen subverts host cell functions by injecting more than 300 different “effector proteins” as well as small signaling molecules (1) (Fig. 1). Our research aims at elucidating the (i) mode of action of effector proteins, (ii) cell-cell communication by small signaling molecules, (iii) persistence and resuscitation mechanisms, and (iv) One Health aspects of Legionella species.

Fig. 1. Legionella pneumophila – Environmental niches, human infection, and intracellular growth.

L. pneumophila colonizes biofilms and replicates in protozoa. Upon inhalation, the pathogen grows within and destroys lung macrophages, thereby causing Legionnaires’ disease. L. pneumophila employs the Icm/Dot type IV secretion system and >300 different “effector proteins” to govern interactions with host cells and to form a unique replication compartment, the “Legionella-containing vacuole” (LCV). Inter-bacterial and inter-kingdom communication is mediated by the organic signaling compound LAI-1 (Legionella autoinducer-1, 3-hydroxypentadecane-4-one) and the inorganic gas nitric oxide (NO). L. pneumophila shows phenotypic heterogeneity and can adopt a persistent, antibiotic-resistant state.

Reference

1. Hilbi, H., and Buchrieser, C. (2022) Microbe Profile: Legionella pneumophila - a copycat eukaryote. Microbiology 168: doi: 10.1099/mic.1090.001142.

Projects

Mode of action of L. pneumophila effector proteins
Cell-cell communication of L. pneumophila
Persistence and resuscitation of L. pneumophila
Environmental Legionella species and One Health

Contact and further information

Prof. Dr. sc. nat Hubert Hilbi

Group members

1. Hubert Hilbi, Ph.D., principal investigator
2. Ana Katic, Ph.D. student, University of Zurich
3. Elizabeth Vittori, Ph.D. student, University of Zurich
4. Camille Schmid , Ph.D. student, University of Zurich
5. Pia Stauffer, Ph.D. student, University of Zurich
6. Tobias Jäggi, Ph. D. student, University of Zurich
7. Tong Chen, Ph. D. student, University of Zurich
8. Luca Langlois, Ph. D. student, University of Zurich
9. Maurizio Catelani, Master student

Funding

• Swiss National Science Foundation (SNF)
• Novartis Foundation for Medical-Biological Research
• Novartis FreeNovation Program
• Swiss Federal Offices for Food Safety and Veterinary Affairs (BLV)
• Swiss Federal Offices for Energy (BFE)
• Geberit AG

Collaborations

• Dörte Becher (University of Greifswald)
• Carmen Buchrieser (Pasteur Institute, Paris)
• Wolfgang Eisenreich (TU Munich)
• Aymelt Itzen (TU Munich)
• Martin Pilhofer (ETH Zürich)
• Jürgen Seibel (University of Würzburg)
• Markus Seeger (University of Zürich)
• Vikram Panse (University of Zürich)
• Julia Vorholt (ETH Zürich)

Photo gallery

Selected Literature

Publications (PDF, 88 KB)