Working group Rickettsiology
The workgroup Rickettsiology deals with the detection of diseases caused by Rickettsiae. These bacteria are transmitted to humans and animals by arthropods, particularly ticks. Among others, Rickettsiae are the causative agents of Rocky Mountain spotted fever (R. rickettsii), different types of tick bite fever and Boutonneuse fever (R. conori). Another genus in the order Rickettsiales is Ehrlichia. This includes canine ehrlichiosis (tropical canine pancytopenia), an infectious disease caused by Ehrlichia canis, which affects monocytes and lymphocytes. The disease which occurs in tropical regions and the Mediterranean area poses a threat to dogs taken along by their owners on vacation trips to these regions. In humans, Anaplasma phagocytophilum causes a febrile disease (human granulocytic anaplasmosis), but the pathogen can also infect dogs (canine anaplasmosis), cats, horses, and ruminants.
Furthermore, the workgroup Rickettsiology also conducts research on other tick-borne diseases which are not caused by Rickettsiae. These include borreliosis (Lyme disease), babesiosis and Q fever (Coxiella burnetti). The causative agent of Lyme disease is a rod-shaped bacterium which affects skin, joints and nervous system and leads to redness of the skin (Erythema migrans), muscular pain and neuropathia. The most important transmitter is the castor bean tick (Ixodes ricinus). The causative agents of babesioses are protozoans parasitizing in the red blood cells of vertebrates. Babesia canis causes babesiosis in dogs, while B. divergens among others affects cattle (red water fever). Human babesiosis is caused by the species B. divergens and B. microti. Important transmitters are also hard ticks of the genus Ixodes.
For information on Q fever please refer to the website of the National Reference Laboratory for Q Fever.
Overview of services
The tasks of the workgroup Rickettsiology include:
- Participation in national and international workgroups and research projects
- Research for improvement and standardization of diagnostics as well as on pathogenesis, immunization and epidemiology
- Collection and analysis of epidemiological data
- Training in diagnostic methods
- Coordination of scientific studies with other laboratories
- Publication and spread of information
- Organization of workshops
- Development and validation of new diagnostic techniques of intracellular bacteria
- Vaccine development for diseases caused by intracellular bacteria
- Study of the host-pathogen-interaction of intracellular bacteria with focus on the Lipopolysaccharide as dominant surface antigen
- Development of molecular methods for characterization of virulence factors and defense mechanisms of intracellular bacteria
- Geno- and phenotypic characterization of intracellular bacteria
Overview of methods
- Pathogen detection in cell culture (Borrelia)
- Genome detection by conventional PCR
- Serological pathogen detection (ELISA)
Coxiella burnetii and Borrelia burgdorferi sensu lato in ticks from Moldavia and Germany
in cooperation with the Institute of Zoology, Chișinău, Moldavia
(supported by BMBF; MD 10/001)
Over the past few years, the importance of tick-borne diseases has increased. These pathogens can be transmitted to a multitude of hosts including humans as well as domestic animals and wildlife. In Europe, Q fever and Lyme disease count among the most important tick-borne diseases. Q fever is caused by the Rickettsial bacterium Coxiella burnetii, while the causative agent of Lyme disease is the spirochete Borrelia burgdorferi sensu lato. The most important vectors for these pathogens are ticks of the genera Ixodes and Dermacentor.
The aim of the study is to investigate the significance of these tick species for the transmission of diseases in Germany and Moldavia in greater detail. For this purpose, ticks are collected in Germany and Moldavia and are investigated by PCR and cell culture for Coxiella burnetti, Borrelia burgdorferi sensu lato and mixed infections with these pathogens.