title: Observation of a novel Babesia spp. in Eastern Grey Kangaroos (Macropus giganteus) in Australia.
abstract: The roles and epidemiological features of tick-borne protozoans are not well elicited in wildlife. Babesia spp. are documented in many domestic animals, including cattle, horses, pigs, dogs and cats. Three cases affecting eastern grey kangaroos are described. The kangaroos exhibited neurological signs, depression and marked anaemia, and microscopic examination of blood smears revealed intraerythrocytic piroplasms. One to seven intraerythrocytic spherical, oval, pyriform and irregularly-shaped parasites consistent with Babesia spp. were seen in the blood smears and the percentage of infected erythrocytes was estimated to be approximately 7% in each case. Data suggest that the tick vector for this kangaroo Babesia sp. is a Haemaphysalis species. For Case 2, ultrastructural examination of the erythrocytes of the renal capillaries showed parasites resembling Babesia spp. and 18 of 33 erythrocytes were infected. DNA sequencing of the amplified 18S rDNA confirmed that the observed intraerythrocytic piroplasms belong to the genus Babesia. The phylogenetic position of this new kangaroo Babesia sp. (de novo Babesia macropus), as a sister species to the new Australian woylie Babesia sp., suggests a close affinity to the described Afro-Eurasian species Babesia orientalis and Babesia occultans suggesting perhaps a common ancestor for the Babesia in kangaroos.
authors.affiliation: Elizabeth Macarthur Agricultural Institute, New South Wales Department of Primary Industries, Woodbridge Road, Menangle, NSW 2568, Australia.
authors.forename: Kaiser E
authors.initials: KE
authors.lastname: Dawood
authors.affiliation: Queensland Alliance for Agriculture & Food Innovation, The University of Queensland, 306 Carmody Road, St. Lucia, Qld 4072, Australia.
authors.forename: Jess A T
authors.initials: JA
authors.lastname: Morgan
authors.affiliation: Moruya Veterinary Hospital, 86-88 Queens St. Moruya, NSW 2537, Australia.
authors.forename: Frances
authors.initials: F
authors.lastname: Busfield
authors.affiliation: Elizabeth Macarthur Agricultural Institute, New South Wales Department of Primary Industries, Woodbridge Road, Menangle, NSW 2568, Australia.
authors.forename: Mukesh
authors.initials: M
authors.lastname: Srivastava
authors.affiliation: Tick Fever Centre, Queensland Department of Agriculture, Fisheries & Forestry, 280 Grindle Road, Wacol, Qld 4076, Australia.
authors.forename: Taryn I
authors.initials: TI
authors.lastname: Fletcher
authors.affiliation: Tick Fever Centre, Queensland Department of Agriculture, Fisheries & Forestry, 280 Grindle Road, Wacol, Qld 4076, Australia.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Sambono
authors.affiliation: Biosecurity Queensland, Queensland Department of Agriculture, Fisheries & Forestry, 39 Kessels Road, Coopers Plains, Qld 4108, Australia.
authors.forename: Louise A
authors.initials: LA
authors.lastname: Jackson
authors.affiliation: Animal Science, Queensland Department of Agriculture, Fisheries & Forestry, 306 Carmody Road, St. Lucia, Qld 4072, Australia.
authors.forename: Bronwyn
authors.initials: B
authors.lastname: Venus
authors.affiliation: Elizabeth Macarthur Agricultural Institute, New South Wales Department of Primary Industries, Woodbridge Road, Menangle, NSW 2568, Australia.
authors.forename: Adrian W
authors.initials: AW
authors.lastname: Philbey
authors.affiliation: Queensland Alliance for Agriculture & Food Innovation, The University of Queensland, 306 Carmody Road, St. Lucia, Qld 4072, Australia.
authors.forename: Ala E
authors.initials: AE
authors.lastname: Lew-Tabor
keywords: Apicomplexan; Babesia; Haematology; Kangaroo