Detection of a Hepatozoon and spotted fever group Rickettsia species in the common marsupial tick (Ixodes tasmani) collected from wild Tasmanian devils (Sarcophilus harrisii), Tasmania

Abstract

Tasmanian devils are the largest extant marsupial carnivores, confined to the Australian island state of Tasmania. The iconic marsupial has dramatically declined in number since the discovery of devil facial tumor disease in 1996 and efforts are being made to uncover vital information to assist in the long-term survival of the species. Ticks are the main vectors of arthropod-borne disease in animals, raising the question of whether Tasmanian devils may be host to arthropods capable of harboring infectious agents. Partially engorged ticks were collected from 35 wild Tasmanian devils and tested for the presence of a range of tick-borne genera. A spotted fever group Rickettsia was detected in 45.5% of samples of the tick Ixodes tasmani (n = 44), from all trapping locations, sharing close sequence identity to members of the Rickettsia massiliae group. A Hepatozoon species was also identified in 34.1% of the same sample set, sharing sequence similarities to Hepatozoon felis, a known pathogen of felids. Dual detection was identified in 13.6% of tick samples, where prevalence of the two genera overlapped. The existence of two previously undetected species of genera known for containing pathogens identifies additional potential risks to the health of the devil population.