Genetic epidemiology and pathology of raccoon-derived Sarcoptes mite from urban areas of Germany

Abstract

Raccoons are an invasive species continuously spreading throughout Europe with Germany as the core area. Here, raccoons mostly live in rural regions, but some urban populations are already established (city of Kassel) or starting to build up (Berlin). The objective of this study was to investigate Sarcoptes infections in racoons in these two urban areas and try to identify the putative origin of the parasite. Parasite morphology, gross and histopathology examinations of diseased skin tissue were consistent with Sarcoptes scabiei infection. Moreover, using 9 microsatellite markers we genotyped individual mites from five raccoons and compared them with fox-, wild boar- and Northern chamois-derived Sarcoptes mites, originating from Italy and Switzerland. The raccoon-derived mites clustered together with the fox samples and were clearly differentiated from those of the wild boar and chamois suggesting a fox origin for the raccoon mange infection. These results are evidence of cross-transmission of S. scabiei among wild carnivores. Although our results cannot elucidate whether raccoons became infected by frequent interaction with endemically or epidemically infected foxes or if these cases were the result of occasional contacts among these animal species. Nevertheless, they show that pathogens can be shared among urban populations of native and invasive carnivores