Chlamydiae in woodlice: Studying microbe-host interaction in the natural environment

Current projects

Chlamydia are well-known pathogens of humans and animals but are also ubiquitous in the environment. Rhabdochlamydia porcellionis infecting the rough woodlouse Porcellio scaber represents a good model system for studying natural chlamydial populations, their genetic heterogeneity, infection and developmental cycle under environmental conditions. The animal host P. scaber is an ecologically important detrivore and survives well in heavy-metal polluted environments.

Aim: To test the hypothesis that naturally virulent and attenuated R. porcellionis populations are characterized by distinct differences with respect to genomic repertoire, host-interaction and virulence, metabolism and heavy-metal resistance.

Approach: A set of R. porcellionis infected woodlouse populations from geographically distinct environments differing in heavy metal concentration is available; R. porcellionis isolates will be characterized by genome and RNA sequencing both in vitro (insect cell lines) and in vivo, proteomics, and microscopy. Rhabdochlamydia genome diversity and host-adaptation will be further studied by large-scale comparative analysis of genomes from symbionts in dwarf spiders (collaboration with Frederik Hendrickx, Royal Belgian Institute of Natural Sciences) and metagenome assembled genomes from public metagenome data.

Relevance: This project will improve our understanding of how environmental factors shape microbe-host relationships; it will deepen our knowledge about elusive pathogens of an ecologically important group of arthropods.

Student: Tamara Halter

Faculty: Matthias Horn (PI), Rattei, Petersen

Funding: uni:docs program at the University of Vienna


Selected Publications:

Horn, M. Chlamydiae as symbionts in eukaryotes. Annu. Rev. Microbiol. 62, 113–131 (2008).

Lagkouvardos, I., Weinmaier, T., Lauro, F. M., Cavicchioli, R., Rattei, T. & Horn, M. Integrating metagenomic and amplicon databases to resolve the phylogenetic and ecological diversity of the Chlamydiae. ISME J. 8, 115–125 (2014).

Sixt, B. S., Kostanjšek, R., Mustedanagic, A., Toenshoff, E. R. & Horn, M. Developmental cycle and host interaction of Rhabdochlamydia porcellionis, an intracellular parasite of terrestrial isopods. Environ. Microbiol. 15, 2980–2993 (2013).

Kostanjsek, R., Strus, J., Drobne, D. & Avgustin, G. ‘Candidatus Rhabdochlamydia porcellionis’, an intracellular bacterium from the hepatopancreas of the terrestrial isopod Porcellio scaber (Crustacea: Isopoda). Int. J. Syst. Evol. Microbiol. 54, 543–549 (2004).