Dr Natasha Speight
Senior Lecturer
School of Animal and Veterinary Science
Faculty of Sciences, Engineering and Technology
Eligible to supervise Masters and PhD - email supervisor to discuss availability.
Dr Natasha Speight is a senior 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 is focused on various aspects of the health and diseases of koalas, including oxalate nephrosis, Chlamydia and retrovirus, and outcomes following bushfire-related burns.
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, particularly in SA koalas (Stephenson et al, 2021).
The Black Summer bushfires in 2019-2020 led to koala deaths in the thousands, but many were also rescued and rehabilitated from their burn injuries. In South Australia, the largest fire was on Kangaroo Island and analysis of medical records showed that 54% of rescued koalas were released following treatment (Dunstan et al, 2021). However, burns can affect deeper tissues of the skin in koalas, and smoke can lead to fluid in their lungs (pulmonary oedema) (Baek et al, 2023). Hence more research is needed to support future bushfire rescue operations.
This research on the health of koalas will contribute to their conservation and management into the future.
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Appointments
Date Position Institution name 2009 - ongoing Senior 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 - -
Education
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) -
Research Interests
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Journals
Year Citation 2024 McDougall, F. K., Speight, N., Funnell, O., Boardman, W. S. J., & Power, M. L. (2024). Dynamics of Antimicrobial Resistance Carriage in Koalas (Phascolarctos Cinereus) and Pteropid Bats (Pteropus Poliocephalus) Before, During and After Wildfires. Microbial Ecology, 87(1), 15 pages.
2024 Hough, I., O'Handley, R., & Speight, N. (2024). Cryptosporidium-associated enteritis in captive koalas (Phascolarctos cinereus). Australian Veterinary Journal, 102(6), 313-315.
2023 Baek, C., Woolford, L., Funnell, O., McLelland, J., Eddy, S., Stephenson, T., & Speight, N. (2023). Cutaneous and Respiratory Lesions in Bushfire-Affected Koalas. Veterinary Sciences, 10(11), 10 pages.
Scopus12023 McDougall, F. K., Boardman, W. S. J., Speight, N., Stephenson, T., Funnell, O., Smith, I., . . . Power, M. L. (2023). Carriage of antibiotic resistance genes to treatments for chlamydial disease in koalas (Phascolarctos cinereus): A comparison of occurrence before and during catastrophic wildfires. One Health, 17, 10 pages.
Scopus1 Europe PMC12023 Blanchard, A. M., Emes, R. D., Greenwood, A. D., Holmes, N., Loose, M. W., McEwen, G. K., . . . Tarlinton, R. E. (2023). Genome Reference Assembly for Bottlenecked Southern Australian Koalas. Genome Biology and Evolution, 15(1), 5 pages.
Scopus4 WoS1 Europe PMC22023 Eisenhofer Philipona, R., Brice, K. L., Blyton, M. D., Bevins, S. E., Leigh, K., Singh, B. K., . . . Moore, B. D. (2023). Individuality and stability of the koala (Phascolarctos cinereus) faecal microbiota through time. PeerJ, 11, e14598-1-e14598-21.
Scopus4 WoS1 Europe PMC32022 Buchanan, C., Woolford, L., Stephenson, T., Hoebergen, M., Kovac, J. H., Breed, W. G., & Speight, N. (2022). TESTIS ABNORMALITIES IN A POPULATION OF SOUTH AUSTRALIAN KOALAS (PHASCOLARCTOS CINEREUS).. Journal of Wildlife Diseases, 58(1), 158-167.
2022 Speight, N. (2022). Health and Diseases of Koalas. Animals, 12(8), 1005.
2022 Tarlinton, R. E., Legione, A. R., Sarker, N., Fabijan, J., Meers, J., McMichael, L., . . . Emes, R. D. (2022). Differential and defective transcription of koala retrovirus indicates the complexity of host and virus evolution.. J Gen Virol, 103(6), 1-17.
Scopus5 WoS2 Europe PMC42021 Stephenson, T., Lee, K., Griffith, J. E., McLelland, D. J., Wilkes, A., Bird, P. S., . . . Woolford, L. (2021). Pulmonary Actinomycosis in South Australian Koalas (Phascolarctos cinereus).. Veterinary Pathology, 58(2), 416-422.
Scopus2 WoS12021 Tarlinton, R. E., Fabijan, J., Hemmatzadeh, F., Meers, J., Owen, H., Sarker, N., . . . Emes, R. D. (2021). Transcriptomic and genomic variants between koala populations reveals underlying genetic components to disorders in a bottlenecked population. Conservation Genetics, 22(3), 329-340.
Scopus6 WoS42021 Stephenson, T., Speight, N., Low, W. Y., Woolford, L., Tearle, R., & Hemmatzadeh, F. (2021). Molecular Diagnosis of Koala Retrovirus (KoRV) in South Australian Koalas (Phascolarctos cinereus). Animals, 11(5), 1-13.
Scopus5 WoS3 Europe PMC22021 Dunstan, E., Funnell, O., McLelland, J., Stoeckeler, F., Nishimoto, E., Mitchell, D., . . . Speight, N. (2021). An analysis of demographic and triage assessment findings in bushfire-affected koalas (Phascolarctos cinereus) on kangaroo island, south australia, 2019–2020. Animals, 11(11), 3237.
Scopus12 WoS6 Europe PMC72020 Downey, P., Caraguel, C., Speight, K. N., Fabijan, J. H., & Boardman, W. S. (2020). Field anaesthesia using alfaxalone and alfaxalone-medetomidine in free ranging koalas (Phascolarctos cinereus), a randomised comparative study.. Veterinary Anaesthesia and Analgesia, 47(3), 368-376.
Scopus3 WoS12020 Sarker, N., Fabijan, J., Owen, H., Seddon, J., Simmons, G., Speight, N., . . . Tarlinton, R. E. (2020). Koala retrovirus viral load and disease burden in distinct northern and southern koala populations.. Sci Rep, 10(1), 263.
Scopus19 WoS16 Europe PMC132020 Butcher, R. G., Pettett, L. M., Fabijan, J., Ebrahimie, E., Mohammadi-Dehcheshmeh, M., Speight, K. N., . . . Trott, D. J. (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, 98(5), 200-206.
Scopus8 WoS7 Europe PMC52020 Fabijan, J., Speight, N., Boardman, W., Hemmatzadeh, F., Trott, D. J., & Woolford, L. (2020). Haematological reference intervals of wild southern Australian koalas (Phascolarctos cinereus).. Aust Vet J, 98(5), 207-215.
Scopus4 WoS3 Europe PMC22020 Fabijan, J., Sarker, N., Speight, N., Owen, H., Meers, J., Simmons, G., . . . Trott, D. J. (2020). Pathological Findings in Koala Retrovirus-positive Koalas (Phascolarctos cinereus) from Northern and Southern Australia. Journal of Comparative Pathology, 176, 50-66.
Scopus19 WoS17 Europe PMC132020 Speight, N., Gates, M., Scriven, J., Stephenson, T., & Woolford, L. (2020). Symmetric dimethylarginine values in koalas (Phascolarctos cinereus) based on oxalate nephrosis status.. Aust Vet J, 98(6), 247-249.
Scopus2 WoS2 Europe PMC12020 Speight, N., Bacci, B., Stent, A., & Whiteley, P. (2020). Histological survey for oxalate nephrosis in Victorian koalas (Phascolarctos cinereus).. Aust Vet J, 98(9), 467-470.
Scopus3 WoS3 Europe PMC32020 Kasimov, V., Stephenson, T., Speight, N., Chaber, A. L., Boardman, W., Easther, R., & Hemmatzadeh, F. (2020). Identification and Prevalence of Phascolarctid Gammaherpesvirus Types 1 and 2 in South Australian Koala Populations. Viruses, 12(9), 12 pages.
Scopus3 WoS2 Europe PMC32019 Immelman, L., Rich, B., & Speight, K. N. (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.
2019 Speight, N., Colella, D., Boardman, W., Taggart, D. A., Haynes, J. I., & Breed, W. G. (2019). Seasonal variation in occurrence of oxalate nephrosis in South Australian koalas (Phascolarctos cinereus). Australian Mammalogy, 41(1), 92-98.
Scopus5 WoS52019 Fabijan, J., Caraguel, C., Jelocnik, M., Polkinghorne, A., Boardman, W. S. J., 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.
Scopus28 WoS19 Europe PMC162019 Speight, K. N., Houston-Francis, M., Mohammadi Dehcheshmeh, M., Ebrahimie, E., Saputra, S., & Trott, D. J. (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.
Scopus5 WoS5 Europe PMC12019 Taggart, P., Fancourt, B., Fabijan, J., Peacock, D., Speight, K., Caraguel, C. G., & McAllister, M. M. (2019). No evidence of toxoplasma gondii exposure in South Australian Koalas (phascolarctos cinereus). Journal of Parasitology, 105(4), 638-641.
Scopus4 WoS2 Europe PMC12019 Fabijan, J., Miller, D., Olagoke, O., Woolford, L., Boardman, W., Timms, P., . . . Speight, K. N. (2019). Prevalence and clinical significance of koala retrovirus in two South Australian koala (Phascolarctos cinereus) populations. Journal of Medical Microbiology, 68(7), 1072-1080.
Scopus20 WoS18 Europe PMC142019 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.
Scopus20 WoS17 Europe PMC142019 Pettett, L. M., Wilson, G. J., Nicolson, V., Boardman, W., Speight, N., Fabijan, J., . . . Bird, P. S. (2019). Malocclusions in the koala (Phascolarctos cinereus).. Australian veterinary journal, 97(11), 473-481.
Scopus3 WoS22018 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.
Scopus18 WoS16 Europe PMC152018 Sarker, N., Fabijan, J., Emes, R. D., Hemmatzadeh, F., Meers, J., Moreton, J., . . . Tarlinton, R. E. (2018). Identification of stable reference genes for quantitative PCR in koalas. Scientific Reports, 8(1), 3364-1-3364-8.
Scopus23 WoS24 Europe PMC182018 Speight, K. N., Hicks, P., Graham, C., Boardman, W., Breed, W. G., 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.
Scopus20 WoS15 Europe PMC92017 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.
Scopus22 WoS15 Europe PMC102017 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.
Scopus16 WoS15 Europe PMC112017 Tarlinton, R. E., Legione, A. R., Sarker, N., Fabijan, J., Meers, J., McMichael, L., . . . Emes, R. D. (2017). Differential and defective expression of Koala Retrovirus indicate complexity of host and virus evolution.
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.
Scopus26 WoS24 Europe PMC152015 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.
Scopus4 WoS42015 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.
Scopus36 WoS35 Europe PMC302014 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.
Scopus18 WoS15 Europe PMC82014 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.
Scopus11 WoS102013 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.
Scopus7 WoS82013 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.
Scopus27 WoS26 Europe PMC13- Speight, N. (n.d.). Koala retrovirus infection and disease in South Australian koala (Phascolarctos cinereus) populations. In Proceedings of the Second Koala Retrovirus Workshop, ed. D. E. Alquezar-Planas, D. P. Higgins, C. L. Singleton, and A. D. Greenwood. Technical Reports of the Australian Museum online, 38, 41-43.
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Conference Papers
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.
Friends of Humane Society International, Canada (2024) Outcomes of koala joeys rescued from bushfire
Humane Society International, Canada (2024) Outcomes of koala joeys rescued from bushfire
SA Department of Environment and Water and KoalaLife (2023): Causes of oxalate nephrosis in koalas
NSW Wildlife Information Rescue and Education Service- WIRES (2022): Gastrointestinal microbiome changes
with the onset and progression of the disease oxalate nephrosis in koalas
Morris Animal Foundation, USA (2020): Clinical assessment of koalas during and following bushfire
Morris Animal Foundation, USA (2016): Prevalence studies of Chlamydia and retrovirus in SA koalas
Nature Foundation SA (2016): Oxalate nephrosis in koalas
Holsworth Wildlife Research Endowment (2009): Oxalate nephrosis in koalas
School of Animal and Veterinary Sciences Research Incentive grants: Oxalate nephrosis in koalas
Veterinary Anatomy and Physiology II
Veterinary Anatomy and Physiology III
Anatomy for Veterinary Technologists I
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Current Higher Degree by Research Supervision (University of Adelaide)
Date Role Research Topic Program Degree Type Student Load Student Name 2024 Principal Supervisor Factors affecting stress hormone concentrations of South Australian Koalas Doctor of Philosophy Doctorate Full Time Mr Connor Patrick Mulligan 2022 Principal Supervisor Dietary, genetic, microbiome and environmental factors contributing to oxalate nephrosis prevalence in South Australian koalas Doctor of Philosophy Doctorate Part Time Miss Evie Dunstan -
Past Higher Degree by Research Supervision (University of Adelaide)
Date Role Research Topic Program Degree Type Student Load Student Name 2016 - 2021 Co-Supervisor Pathology, coinfections and oncogenesis in South Australian koalas (Phascolarctos cinereus) and their association with koala retrovirus (KoRV) Doctor of Philosophy Doctorate Full Time Dr Tamsyn Louise Stephenson 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 Dr Jessica Helen Kovac
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Memberships
Date Role Membership Country 2008 - ongoing Member Wildlife Disease Association Australia 2008 - ongoing Member Australian Mammal Society Australia
Connect With Me
External Profiles