Molecular characterization of Cryptosporidium and Giardia from the Tasmanian devil (Sarcophilus harrisii)

Abstract

The Tasmanian devil (Sarcophilus harrisii) is a carnivorous marsupial found only in the wild in Tasmania, Australia. Tasmanian devils are classified as endangered and are currently threatened by devil facial tumour disease, a lethal transmissible cancer that has decimated the wild population in Tasmania. To prevent extinction of Tasmanian devils, conservation management was implemented in 2003 under the Save the Tasmanian Devil Program. This study aimed to assess if conservation management was altering the interactions between Tasmanian devils and their parasites. Molecular tools were used to investigate the prevalence and diversity of two protozoan parasites, Cryptosporidium and Giardia, in Tasmanian devils. A comparison of parasite prevalence between wild and captive Tasmanian devils showed that both Cryptosporidium and Giardia were significantly more prevalent in wild devils (p < 0.05); Cryptosporidium was identified in 37.9% of wild devils but only 10.7% of captive devils, while Giardia was identified in 24.1% of wild devils but only 0.82% of captive devils. Molecular analysis identified the presence of novel genotypes of both Cryptosporidium and Giardia. The novel Cryptosporidium genotype was 98.1% similar at the 18S rDNA to Cryptosporidium varanii (syn. C. saurophilum) with additional samples identified as C. fayeri, C. muris, and C. galli. Two novel Giardia genotypes, TD genotype 1 and TD genotype 2, were similar to G. duodenalis from dogs (94.4%) and a Giardia assemblage A isolate from humans (86.9%). Giardia duodenalis BIV, a zoonotic genotype of Giardia, was also identified in a single captive Tasmanian devil. These findings suggest that conservation management may be altering host-parasite interactions in the Tasmanian devil, and the presence of G. duodenalis BIV in a captive devil points to possible human-devil parasite transmission.

Cryptosporidium viatorum from the native Australian swamp rat Rattus lutreolus - An emerging zoonotic pathogen?

“…environmental water samples from Canada ( Ruecker et al, 2012 , Ruecker et al, 2013 , Prystajecky et al, 2014 ) and the strongly-supported (BP = 98%) marsupial clade representing sequences of C. fayeri and Cryptosporidium sp. opossum genotype ( Morgan et al, 1999 , Xiao et al, 2002 , Power et al, 2004 , Wait et al, 2017 ).…”

Anthropozoonotic significance, risk factors and spatial distribution of Giardia spp. infections in quenda (Isoodon obesulus) in the greater Perth region, Western Australia

“…Giardia peramelis has not been isolated from other endemic Australian species tested for Giardia spp. (McCarthy et al, 2008; Thompson et al, 2008; Thompson et al, 2010; Ng et al, 2011; Thomasz, 2014; Vermeulen et al, 2015; Wait et al, 2017).…”

Wildlife parasitology in Australia: past, present and future

“…xiaoi (Yang et al 2011). Novel genotypes of Cryptosporidium have been identified in captive and wild Tasmanian devils (Wait et al 2017). However, their extent in the endemic fauna and their zoonotic significance remain uncertain.…”

“…Zoonotic forms of Giardia duodenalis were the only other species found, implying that native mammals in Western Australia, with the exception of the quenda, do not harbour distinct strains of Giardia, as occurs in Tasmania. Novel genotypes of Giardia have been identified in captive and wild Tasmanian devils (Wait et al 2017). The occurrence of zoonotic genotypes in marsupials in the four southern states implies transmission routes between humans and wildlife and vice versa (Thompson et al 2008;Vermeulen et al 2015;Wait et al 2017).…”