School of Animal and Veterinary Science
Faculty of Sciences
Eligible to supervise Masters and PhD - email supervisor to discuss availability.
Dr Natasha Speight is a lecturer at the School of Animal and Veterinary Sciences and is a registered veterinarian. Her current research focuses on the biology, health and diseases of South Australian populations of koalas, particularly oxalate nephrosis.
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My research focuses on the health and diseases of koalas, particularly oxalate nephrosis, Chlamydia and retrovirus.
Oxalate nephrosis, a disease in which calcium oxalate crystals are deposited in the kidneys leading to renal dysfunction (Speight et al, 2013;2014), affects many koalas in the Mount Lofty Ranges population of South Australia. Oxalate nephrosis may have an underlying genetic cause, as well as involve other factors including dietary oxalate (Speight et al, 2013), climate (Speight et al, 2018) and gut bacteria (Speight et al, 2019). Understanding the cause and risk factors of this disease will assist with diagnosis and management of affected koalas.
Chlamydial disease in koalas is devastating populations of koalas on the east coast of Australia. Our research has shown that Chlamydial infection is common in koalas in the Mount Lofty Ranges of South Australia, but causes little disease in these koalas (Speight et al, 2016; Fabijan et al, 2019a). Kangaroo Island koalas have been shown to be Chlamydia pecorum- free, making them a large isolated population of negative koalas (Fabijan et al, 2019a). Understanding more about the infection patterns of Chlamydia in southern koalas will assist with managing this infectious threat to koalas.
Koala retrovirus infects 100% koalas in the eastern states, where it has been shown to be endogenous. In South Australia, koalas have a lower prevalence of retrovirus infection (Fabijan et al, 2019b), and research is continuing to understand its impact in southern koalas, which is based on complex factors such as variant and infection load (Sarker et al, 2019). Koala retrovirus has been associated with the development of lymphoid cancers and may increase the likelihood of Chlamydial infection, so it is important to understand the transmission and disease risk of this infection in SA koalas.
This research on the diseases of koalas will help with their conservation and management into the future.
Date Position Institution name 2009 Lecturer University of Adelaide
Awards and Achievements
Date Type Title Institution Name Country Amount 2014 Award 2014 CL Davis Foundation Journal Award American College of Veterinary Pathologists United States —
Date Institution name Country Title — University of Adelaide Australia PhD — University of Adelaide Australia Honours — Murdoch University Australia BVMS — Murdoch University Australia BSc (Vet Biology)
Year Citation 2020 Sarker, N., Fabijan, J., Owen, H., Seddon, J., Simmons, G., Speight, N., . . . Tarlinton, R. (2020). Koala retrovirus viral load and disease burden in distinct northern and southern koala populations. Scientific Reports, 10(1), 263.
2020 Butcher, R., Pettett, L., Fabijan, J., Ebrahimie, E., Mohammadi-Dehcheshmeh, M., Speight, K., . . . Trott, D. (2020). Periodontal disease in free-ranging koalas (Phascolarctos cinereus) from the Mount Lofty Ranges, South Australia, and its association with koala retrovirus infection. Australian Veterinary Journal, 7 pages.
2020 Fabijan, J., Speight, N., Boardman, W., Hemmatzadeh, F., Trott, D., & Woolford, L. (2020). Haematological reference intervals of wild southern Australian koalas (Phascolarctos cinereus). Australian Veterinary Journal.
2019 Speight, N., Colella, D., Boardman, W., Taggart, D., Haynes, J., & Breed, W. (2019). Seasonal variation in occurrence of oxalate nephrosis in South Australian koalas (Phascolarctos cinereus). Australian Mammalogy, 41(1), 92-98.
DOI Scopus1 WoS1
2019 Fabijan, J., Caraguel, C., Jelocnik, M., Polkinghorne, A., Boardman, W., Nishimoto, E., . . . Speight, N. (2019). Chlamydia pecorum prevalence in South Australian koala (Phascolarctos cinereus) populations: identification and modelling of a population free from infection. Scientific Reports, 9(1), 6261-1-6261-11.
DOI Scopus6 WoS4 Europe PMC1
2019 Speight, K., Houston-Francis, M., Mohammadi Dehcheshmeh, M., Ebrahimie, E., Saputra, S., & Trott, D. (2019). Oxalate-degrading bacteria, including Oxalobacter formigenes, colonise the gastrointestinal tract of healthy koalas (Phascolarctos cinereus) and those with oxalate nephrosis. Australian Veterinary Journal, 97(5), 166-170.
2019 Taggart, P., Fancourt, B., Fabijan, J., Peacock, D., Speight, K., Caraguel, C., & McAllister, M. (2019). No evidence of toxoplasma gondii exposure in South Australian Koalas (phascolarctos cinereus). Journal of Parasitology, 105(4), 638-641.
2019 Fabijan, J., Miller, D., Olagoke, O., Woolford, L., Boardman, W., Timms, P., . . . Speight, K. (2019). Prevalence and clinical significance of koala retrovirus in two South Australian koala (Phascolarctos cinereus) populations. Journal of Medical Microbiology, 68(7), 1072-1080.
DOI Scopus4 WoS2 Europe PMC1
2019 Sarker, N., Fabijan, J., Seddon, J., Tarlinton, R., Owen, H., Simmons, G., . . . Meers, J. (2019). Genetic diversity of Koala retrovirus env gene subtypes: insights into northern and southern koala populations. The Journal of general virology, 100(9), 1328-1339.
DOI Scopus4 WoS2 Europe PMC1
2019 Pettett, L., Wilson, G., Nicolson, V., Boardman, W., Speight, N., Fabijan, J., . . . Bird, P. (2019). Malocclusions in the koala (Phascolarctos cinereus).. Australian veterinary journal, 97(11), 473-481.
DOI Scopus1 WoS1
2019 Downey, P., Caraguel, C., Speight, K. N., Fabijan, J. H., & Boardman, W. S. (2019). Field anaesthesia using alfaxalone and alfaxalone-medetomidine in free ranging koalas (Phascolarctos cinereus), a randomised comparative study.. Veterinary Anaesthesia and Analgesia. 2019 Immelman, L., Rich, B., & Speight, K. (2019). Changes in antioxidant capacity of koalas (Phascolarctos cinereus) based on health status and measurement of the antioxidant ascorbate in eucalypt leaves. Journal of Zoo and Wildlife Medicine, 50(4), 861-867.
2018 Olagoke, O., Miller, D., Hemmatzadeh, F., Stephenson, T., Fabijan, J., Hutt, P., . . . Timms, P. (2018). Induction of neutralizing antibody response against koala retrovirus (KoRV) and reduction in viral load in koalas following vaccination with recombinant KoRV envelope protein. npj Vaccines, 3(1), 30-1-30-8.
DOI Scopus4 WoS3 Europe PMC3
2018 Sarker, N., Fabijan, J., Emes, R., Hemmatzadeh, F., Meers, J., Moreton, J., . . . Tarlinton, R. (2018). Identification of stable reference genes for quantitative PCR in koalas. Scientific Reports, 8(1), 3364-1-3364-8.
DOI Scopus8 WoS6 Europe PMC5
2018 Speight, K., Hicks, P., Graham, C., Boardman, W., Breed, W., Manthorpe, E., . . . Woolford, L. (2018). Necropsy findings of koalas from the Mount Lofty Ranges population in South Australia. Australian Veterinary Journal, 96(5), 188-192.
DOI Scopus6 WoS3 Europe PMC2
2017 Speight, K., Whiteley, P., Woolford, L., Duignan, P., Bacci, B., Lathe, S., . . . Stevenson, M. (2017). Outbreaks of sarcoptic mange in free-ranging koala populations in Victoria and South Australia: a case series. Australian Veterinary Journal, 95(7), 244-249.
DOI Scopus8 WoS8 Europe PMC3
2017 Fabijan, J., Woolford, L., Lathe, S., Simmons, G., Hemmatzadeh, F., Trott, D., & Speight, N. (2017). Lymphoma, Koala Retrovirus Infection and Reproductive Chlamydiosis in a Koala (Phascolarctos cinereus). Journal of Comparative Pathology, 157(2-3), 188-192.
DOI Scopus5 WoS5 Europe PMC4
2016 Speight, K., Polkinghorne, A., Penn, R., Boardman, W., Timms, P., Fraser, T., . . . Woolford, L. (2016). The prevalence and pathological features of Chlamydia pecorum infections in South Australian koalas (Phascolarctos cinereus). Journal of Wildlife Diseases, 52(2), 301-306.
DOI Scopus15 WoS14 Europe PMC9
2015 Speight, K., Kokkinn, M., & Breed, W. (2015). The gastrointestinal tract of the Australian water rat (Hydromys chrysogaster) – its morphological adaptations to a carnivorous diet. Australian Mammalogy, 38(1), 52-57.
DOI Scopus3 WoS2
2015 Jelocnik, M., Bachmann, N., Kaltenboeck, B., Waugh, C., Woolford, L., Speight, K., . . . Polkinghorne, A. (2015). Genetic diversity in the plasticity zone and the presence of the chlamydial plasmid differentiates Chlamydia pecorum strains from pigs, sheep, cattle, and koalas. BMC Genomics, 16(1), 893-1-893-14.
DOI Scopus17 WoS19 Europe PMC16
2014 Speight, K., Haynes, J., Boardman, W., Breed, W., Taggart, D., Rich, B., & Woolford, L. (2014). Plasma biochemistry and urinalysis variables of koalas (Phascolarctos cinereus) with and without oxalate nephrosis. Veterinary Clinical Pathology, 43(2), 244-254.
DOI Scopus9 WoS8 Europe PMC4
2014 Graham, C., Woolford, L., Johnson, L., & Speight, K. (2014). Age-dependent changes in gross and histological morphology of the thyroid gland in South Australian koalas (Phascolarctos cinereus). Australian Journal of Zoology, 62(5), 360-365.
2013 Speight, K., Breed, W., Boardman, W., Taggart, D., Leigh, C., Rich, B., & Haynes, J. (2013). Leaf oxalate content of Eucalyptus spp. and its implications for koalas (Phascolarctos cinereus) with oxalate nephrosis. Australian Journal of Zoology, 61(5), 366-371.
DOI Scopus8 WoS8
2013 Breed, W., Leigh, C., & Speight, K. (2013). Coevolution of the male and female reproductive tracts in an old endemic murine rodent of Australia. Journal of Zoology, 289(2), 94-100.
DOI Scopus6 WoS6
2013 Speight, K., Boardman, W., Breed, W., Taggart, D., Woolford, L., & Haynes, J. (2013). Pathological features of oxalate nephrosis in a population of koalas (Phascolarctos cinereus) in South Australia. Veterinary Pathology, 50(2), 299-307.
DOI Scopus17 WoS16 Europe PMC11
Year Citation 2011 Speight, K. N., Breed, W., Taggart, D. A., McCarthy, P., Rich, B., Boardman, W. S. J., & Haynes, J. (2011). Oxalate nephrosis in koalas in the Adelaide Hills. In Proceedings of the Wildlife Disease Association Australasian section Conference. Coorong. 2010 Speight, K. N., Haynes, J., Breed, W., Taggart, D., Boardman, W. S., & Rich, B. (2010). Eucalypts as a possible source of oxalate for koalas suffering from oxalate nephrosis. In Proceedings of Australian Mammal Society (pp. 18). Canberra.
Morris Animal Foundation, USA: Prevalence studies of Chlamydia and retrovirus in SA koalas
Nature Foundation SA: Oxalate nephrosis in koalas
Holsworth Wildlife Research Endowment: Oxalate nephrosis in koalas
Veterinary Anatomy and Physiology II
Veterinary Anatomy and Physiology III
Anatomy for Veterinary Technologists
Current Higher Degree by Research Supervision (University of Adelaide)
Date Role Research Topic Program Degree Type Student Load Student Name 2018 Principal Supervisor Oxalate Nephrosis in Koalas Doctor of Philosophy Doctorate Full Time Miss Kyneta Bhoola 2016 Co-Supervisor Molecular Pathogenesis of Oncogenesis in KoRV Infected Koalas Doctor of Philosophy Doctorate Full Time Dr Tamsyn Louise Stephenson
Past Higher Degree by Research Supervision (University of Adelaide)
Date Role Research Topic Program Degree Type Student Load Student Name 2015 - 2020 Co-Supervisor Prevalence and Pathological Findings Associated with Chlamydia pecorum and Koala Retrovirus Infections in South Australian Koala Populations Doctor of Philosophy Doctorate Full Time Jessica Helen Fabijan
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