Rickettsia spp. in small mammals and their parasitizing ectoparasites from Saxony, Germany

Anna Obiegala; Carolin Oltersdorf; Cornelia Silaghi; Daniel Kiefer; Matthias Kiefer; Dietlinde Woll; Martin Pfeffer

doi:10.1016/j.vprsr.2016.08.008

Rickettsia spp. in small mammals and their parasitizing ectoparasites from Saxony, Germany

Vet Parasitol Reg Stud Reports. 2016 Sep:5:19-24. doi: 10.1016/j.vprsr.2016.08.008. Epub 2016 Sep 1.

Authors

Anna Obiegala¹, Carolin Oltersdorf², Cornelia Silaghi³, Daniel Kiefer³, Matthias Kiefer⁴, Dietlinde Woll², Martin Pfeffer²

Affiliations

¹ Institute of Animal Hygiene and Veterinary Public Health, University of Leipzig, An den Tierkliniken 1, 04103 Leipzig, Germany. Electronic address: Anna.Obiegala@vetmed.uni-leipzig.de.
² Institute of Animal Hygiene and Veterinary Public Health, University of Leipzig, An den Tierkliniken 1, 04103 Leipzig, Germany.
³ Comparative Tropical Medicine and Parasitology, Ludwig-Maximilians-Universität München, Leopoldstraße 5, 80802 Munich, Germany.
⁴ The Bavarian State Collection of Zoology, Munich, Germany.

PMID: 31014532
DOI: 10.1016/j.vprsr.2016.08.008

Abstract

Rickettsiae are emerging pathogens causing various types of spotted fever and typhus and are mostly transmitted by arthropods to humans and animals. In order to investigate the distribution of Rickettsiae of the spotted fever group (SFG) in small mammals as potential reservoirs and in fleas and ticks from these animals as potential vectors, a total of 91 small mammals (seven species) were captured and their ectoparasites were collected at seven sites around Leipzig, Saxony, Germany, in 2010 and 2011. Altogether, 91 skin samples, 125 fleas (five species) and 363 ticks (four species) were investigated for DNA of Rickettsia spp. with a real-time PCR targeting the gltA gene. A total of 26 (28.6%) rodents, 5 (3.9%) fleas and 151 (41.6%) ticks were positive for Rickettsia spp. by real-time PCR. Altogether 42 positive tick-, and all positive small mammal- and flea-samples were further determined to Rickettsia species level with a conventional PCR targeting the ompB gene followed by sequencing. Sequencing of 14 positive rodent samples revealed R. helvetica (n=12) and R. raoultii (n=2). Three Rickettsia spp. were detected in ticks: Rickettsia raoultii (59.6%), R. monacensis (4.8%) and R. helvetica (33.3%). In total 85.6% of Dermacentor reticulatus ticks and 20.4% of Ixodes ricinus ticks were positive. Rickettsia raoultii was found in 4 of the 5 positive fleas. To our knowledge this is the first detection of R. raoultii in Myodes glareolus and of R. helvetica in Apodemus agrarius from Germany. The high prevalence of R. helvetica in small mammals suggests that they may play an important role as potential natural reservoir hosts. The high prevalence in engorged I. ricinus for R. helvetica and in D. reticulatus ticks for R. raoultii, mostly deriving from uninfected mammals, leads to the conclusion that those tick species may serve as vectors for those Rickettsia spp. Detection of R. raoultii in fleas, parasitizing on their small mammal hosts, may indicate accidental uptake during feeding on hosts with bacteraemia rather than an active involvement of fleas in the transmission cycle of this Rickettsia species.

Keywords: Dermacentor reticulatus; Ixodes ricinus; Myodes glareolus.