Investigation of skin samples from red foxes (Vulpes vulpes) in eastern Brandenburg (Germany) for the detection of Borrelia burgdorferi s. l.

During earlier investigations a high prevalence of Borrelia (B.) burgdorferi s. l. in unfed Ixodes (I.) ricinus ticks in the Federal State of Brandenburg has been demonstrated. In the present study skin samples were obtained from 100 red foxes (Vulpes vulpes) from the districts where the highest B. burgdorferi prevalences had previously been found (i.e. Uckermark, Barnim, Märkisch-Oderland, Oder-Spree). BSK- and MKP-medium including inhibitory substances were used for cultivation of spirochaetes. Non-motile spirochaete-like organisms were observed in 26% of the samples. Additionally, by subcultures it was not possible to obtain motile helical forms characteristic for B. burgdorferi. On tryptose agar, the bacteria which produced nonmotile forms appeared as corynebacterium-like-colonies. Investigations by electron microscopy showed that the immobile spiral forms were giant whips (flagellae) which belonged to the contaminant flora. These forms proved to be negative for B. burgdorferi s. l. by the use of a nested-PCR. In a further study, the same skin samples were investigated for the presence of B. burgdorferi s. l.-DNA using a nested-PCR. Seven out of 100 samples were positive.