Rickettsia aeschlimannii in Hyalomma marginatum Ticks, Germany

Fragile transmission cycles of tick-borne encephalitis virus may be disrupted by predicted climate change. Rickettsia aeschlimannii in Hyalomma marginatum Ticks, Germany To the Editor: Rickettsia spp. of the spotted fever group cause worldwide emerging human infections known as tick-borne rickettsioses (1). Data on the occurrence and prevalence of Rickettsia in Germany are still limited (2). Six Rickettsia species have been reported to date (2). R. helvetica, R. felis, R. massiliae, and R. mona-censis were detected with a relatively low prevalence in Ixodes ricinus ticks collected in southern Germany (2); R. raoultii was identifi ed with high prevalence in the rapidly expanding area where D. reticulatus ticks are found (2). R. raoultii was recently recognized as an agent of tick-borne lymph-adenopathy/Dermacentor-borne necrosis and erythema lymphadenop-athy (3). Low prevalence of another tick-borne lymphadenopathy agent, R. slovaca, in Dermacentor marginatus ticks collected in southern Germany was recently reported (4). We report the detection in Germa-ny of the pathogenic SFG species R. aeshlimannii (1), which is phylogenet-ically close to R. raoultii and causes an infection with clinical signs similar to those of Mediterranean spotted fever (1). To determine the prevalence of R. raoultii in the ticks in Berlin/ Brandenburg and neighboring regions , we collected 294 ticks; 288 had been collected either from vegetation or domestic animals and morphologically identifi ed as adult D. reticulatus ticks. The remaining 6 ticks were delivered by an ornithologist who had removed them from a bird (belonging to the Acrocephalus scirpaceus spp.) that he had captured in the reeds near Pakendorf and Zerbst, Saxony-Anhalt, in May 2007. These 6 ticks were reported as D. reticulatus–like adults but were damaged in the collection process, making an exact morphologic evaluation impossible. DNA was isolated from the complete tick body by homogenization in the SpeedMill (Analytik Jena Biosolu-tions, Jena, Germany) followed by pu-rifi cation by RapideStripe tick DNA/ RNA Extraction Kit (Analytik Jena Biosolutions). Multispacer typing (5) was used for molecular detection and determination of Rickettsia spp. (Figure). DNA sequencing and analysis were performed as described (Figure). In 51.3% of the intact tick isolates, R. raoultii was detected. In each of the 3 damaged isolates, the multispacer type pattern was detected, which was 100% identical to that of R. aeschli-mannii (5) (Figure). Moreover, PCR, which we routinely use as a positive control for molecular identifi cation of D. reticulatus, yielded no product in the damaged isolates (Figure). To determine the species …