Molecular surveillance of piroplasms in ticks from small and medium-sized urban and peri-urban mammals in Australia

Abstract

Natural landscape alterations as a consequence of urbanisation are one of the main drivers in the movements of wildlife into metropolitan and peri-urban areas. Worldwide, these wildlife species are highly adaptable and may be responsible for the transmission of tick-borne pathogens including piroplasms (Babesia, Theileria and Cytauxzoon spp.) that cause piroplasmosis in animals and occasionally in humans. Little is known about piroplasms in the ticks of urban wildlife in Australia. Ticks from long-nosed bandicoots (Perameles nasuta; n = 71), eastern-barred bandicoots (Perameles gunnii; n = 41), northern-brown bandicoots (Isoodon macrourus; n = 19), southern-brown bandicoots (Isoodon obesulus; n = 4), bandicoot sp. (n = 2), flying foxes (Pteropus sp.; n = 3), black rats (Rattus rattus; n = 7), bush rats (Rattus fuscipes; n = 4), brushtail possums (Trichosurus vulpecula; n = 19), ringtail possums (Pseudocheirus peregrinus; n = 12), short-eared possums (Trichosurus caninus; n = 6), possum sp. (Trichosurus sp.; n = 8), and red foxes (Vulpes vulpes; n = 12) were analysed using piroplasm-specific 18S primers and Sanger sequencing. Seven Ixodes tasmani ticks from long-nosed bandicoots and bandicoots sp., three I. tasmani ticks and one Ixodes holocyclus tick from brushtail possums, and one Haemaphysalis longicornis tick from a red fox were positive for piroplasms. New genotypes, with sequences sharing 98% nucleotide similarities with Theileria sp. K1 detected in a burrowing bettong (Bettongia lesueur), were identified from bandicoot ticks. New genotypes were detected in ticks from brushtail possums, which shared 98% similarity with a Babesia sp. (JQ682877) previously identified in marsupials. Theileria orientalis was identified in the H. longicornis tick from the red fox. Babesia and Theileria spp. in the ticks parasitizing bandicoots and brushtail possums clustered closely with respective Babesia and Theileria clades derived from Australian marsupials. This represents the first detection of piroplasms in ticks parasitizing brushtail possums and a red fox in Australia.

Sequence analyses at mitochondrial and nuclear loci reveal a novel Theileria sp. and aid in the phylogenetic resolution of piroplasms from Australian marsupials and ticks

“…Of these, two lineages were first revealed by recent phylogenetic studies based on nearly full-length 18S sequences from Theileria spp. isolated from Australian native marsupials, monotremes and ticks [6, 7, 19–21].…”

Blood Parasites in Endangered Wildlife-Trypanosomes Discovered during a Survey of Haemoprotozoa from the Tasmanian Devil

“…are transmitted by ticks and, therefore, dependent on the density and interactions between host and vector(s) to continue their lifecycle. Recent investigations have revealed the presence of numerous novel Babesia , Theileria , and Hepatozoon species in native Australian ticks [ 78 , 79 , 80 ]. With respect to the single identification of Babesia at the Black River site, the genetic relationship shows that it is most closely related to Babesia lohae sequences identified in Ixodes holocyclus and Ixodes tasmani ticks from the east coast of Queensland [ 78 , 79 ].…”

“…Recent investigations have revealed the presence of numerous novel Babesia , Theileria , and Hepatozoon species in native Australian ticks [ 78 , 79 , 80 ]. With respect to the single identification of Babesia at the Black River site, the genetic relationship shows that it is most closely related to Babesia lohae sequences identified in Ixodes holocyclus and Ixodes tasmani ticks from the east coast of Queensland [ 78 , 79 ]. The low prevalence of Babesia might be attributed to the seasonality of tick infestations, as has been described in the relationship between I. tasmani ticks and brushtail possums hosts [ 81 ].…”

“…[ 84 ]. More recently, novel species of Theileria and Hepatozoon were identified from I. tasmani collected in Tasmania [ 78 , 79 ]. Given the high prevalence of I. tasmani parasitising sampled Tasmanian devils (Ruiz-Aravena pers.…”

Mapping the Potential Distribution of Major Tick Species in China

“…For example, the tick-borne encephalitis virus had caused widespread infections in East Europe, West Europe, Middle Europe, and Russia [ 3 , 4 ]. Since ticks can inhabit a wide range of vegetated habitats in the countryside, suburbs or even urban areas [ 5 , 6 , 7 ], they are posing threats to public and veterinary health wherever their population is established.…”