Research Projects - Bacteriology
Epidemiology and immunology of arthropod-borne bacterial infections
The research group investigates the epidemiology and immunology (antibody, cytokine and cellular responses) of arthropod-borne bacterial pathogens such as Rickettsia typhi and R. prowazekii, Orientia tsutsugamushi, Coxiella burnetii, Francisella tularensis, and Yersinia pestis.
With a focus on rickettsioses, we conduct studies in Malaysia, Tanzania, the Democratic Republic of the Congo and Madagascar together with our international partners. Moreover, cohorts of returning travellers with various forms of rickettsioses, scrub typhus, as well as patients with autochthonously acquired tularemia and Q fever are analyzed.
For a list of the group's publications about rickettsioses, click here. More information (in German) about ticks and their respective pathogens which are diagnosed at our National Reference Center can be found here. For a list of the group's publications about ticks, click here.
Epidemiological studies of rickettsioses
Typhus group rickettsiosis is caused by Rickettsia typhi and R. prowazekii. R. typhi, which causes murine typhus, the less severe endemic form of typhus, is transmitted by fleas; R. prowazekii, which causes the severe epidemic form of typhus, is transmitted by body lice. In contrast, the spotted fever group rickettsiae, such as R. africae and many other members of this group, are harbored by ticks.
Besides ongoing prevelance studies in the arthropod vectors, seroprevalence and cohort studies in humans are conducted. The occurance of the pathogens in vectors and their prevalence in human disease are not always congruent and hint a local modifying factors.
For a list of the group's publications on rickettsial epidemiology, click here.
Immunological studies of rickettsioses
To learn more about the immunology of human infection with various forms of rickettsioses, and also scrub typhus, we analyzed respective patient cohorts. Clinical data was evaluated and patient serum was examined for antibody kinetics, serum cytokine changes, and, in one cohort, also T cell responses.
Mixed cytokine responses were detected in the cohorts, and cytokine levels peaked during the second and third week of infection with typhus group rickettsiae, coinciding with seroconversion and organ dysfunction, respectively.
For a list of the group's publications on rickettsial immunology, click here.