Publications

Chlamydial disease

Marschner C, Flanagan C, Higgins DP, Krockenberger MB "Validation of ultrasonography in detecting structural disease of the urogenital tract of the koala" (In Press) [[i||Australian Veterinary Journal (accepted 5/10/13)

Griffith JE, Dhand NK, Krockenberger MB, Higgins DP (2103) A Retrospective Study of Admission Trends of Koalas to a Rehabilitation Facility over Thirty Years. Journal of Wildlife Diseases 49:18-28. doi:10.7589/2012-05-135
Analysis of case records for koala admission, describing risk factors for admission of koalas, including age, sex, season and ongoing urban development, and relative prevalence of key diseases amongst admitted koalas.

Higgins DP, Beninati T, Meek M, Irish J, Griffith JE (2012) Within-population diversity of koala Chlamydophila pecorum at ompA VD1-VD3 and the ORF663 hypothetical gene. Veterinary Microbiology 156: 353–358
First study focusing on chlamydial diversity within a fragmented koala population. Describes minor divergence of chlamydial ompA strains in neighboring habitat fragments and diversity of hypothetical virulence genes within populations. Relevant to koala movement, and relationships between habitat fragmentation and pathogen diversity and virulence.

Griffith JE, Higgins DP (2012) Diagnosis, treatment and outcomes for koala chlamydiosis at a rehabilitation facility (1995 - 2005). Australian Veterinary Journal 90 (11): 457-463. doi: 10.1111/j.1751-0813.2012.00963.x
Analysis of case records of koala treatment. Provides evidence base for the value of koala care and rehabilitation, and the need for greater research and veterinary support.

Higgins DP, Hemsley S, Canfield PJ (2005) Immunohistochemical demonstration of the role of Chlamydia spp. in renal, uterine and salpingeal disease of the koala, and demonstration of Chlamydia spp. in novel sites. Journal of Comparative Pathology 133:164-174.
Confirmation of Chlamydia’s direct role in disease of the upper reproductive tract and kidney of the koala, as opposed to other bacteria invading secondary to chlamydial disease of the lower urogenital tract.

Higgins DP, Hemsley S, Canfield PJ (2005) Association of uterine and salpingeal fibrosis with chlamydial hsp60 and hsp10 antigen-specific antibodies in Chlamydia-infected koalas. Clinical and Diagnostic Laboratory Immunology 12(5): 632-639.
First immunological evidence of association of Th2 mediated responses and chlamydial heat shock antigens in pathogensis of uterine fibrosis and infertility in koalas; thus supporting assumption that persistence and re-infection, and Th1/Th2 balance play a role in pathogenesis in koalas, as in humans.

Cryptococcosis

Jobbins, S.E., C. Hill, J.M. D’Souza-Basseal, M. Padula, B.R. Herbert and M.B. Krockenberger (2010). An immunoproteomic approach to elucidating the pathogenesis of Cryptococcosis caused by Cryptococcus gattii. Journal of Proteomics Research 9:3832-3841 http://pubs.acs.org/doi/suppl/10.1021/pr100028t

Saul N, Krockenberger M, Carter D (2008). Evidence of recombination in mixed mating type and a-only populations of Cryptococcus gattii sourced from single Eucalyptus tree hollows. Eukaryotic Cell 7(4):727-734

Krockenberger, M.B., K. Stalder, P.J. Canfield and R. Malik (2005). Cryptococcosis of Australian Wildlife. Microbiology Australia 26(2):69-71

Krockenberger, M.B., P.J. Canfield and R. Malik (2003). Cryptococcus neoformans var. gattii in the koala (Phascolarctos cinereus): A review of 43 cases of cryptococcosis. Medical Mycology 41:225-234.

Krockenberger, M.B., P.J. Canfield, J. Barnes, L. Vogelnest, J. Connolly, C. Ley and R. Malik (2002). Cryptococcus neoformans in the koala (Phascolarctos cinereus): Serological evidence for subclinical cryptococcosis. Medical Mycology 40:273-282

Krockenberger, M.B., P.J. Canfield and R. Malik (2002). Cryptococcus neoformans in the koala (Phascolarctos cinereus): Colonisation by variety gattii and investigation of environmental sources. Medical Mycology 40:263-272

Krockenberger, M.B., P.J. Canfield and R. Malik (2002). What koalas are trying to tell us about cryptococcosis. Microbiology Australia 23(3):29-30.

Vilcins, I., M. Krockenberger, H. Agus and D. Carter (2002). Environmental sampling for Cryptococcus neoformans var. gattii from the Blue Mountains National Park, Sydney, Australia. Medical Mycology 40: 53-60

Krockenberger, M.B., P.J. Canfield, T.R. Kozel, R. Ikeda, T. Shinoda, D. Wigney, P. Martin, K. Wadwell and R. Malik (2001). An immunohistochemical method to differentiate between Cryptococcus neoformans varieties and serotypes in formalin-fixed paraffin-embedded tissues. Medical Mycology 39: 523-533.

Connolly, J.H., M.B. Krockenberger, R. Malik, P.J. Canfield, D.I. Wigney and D.B. Muir (1999). Asymptomatic carriage of Cryptococcus neoformans in the nasal cavity of the koala (Phascolarctos cinereus). Medical Mycology 37(5): 331-338

Pharmacokinetics of therapeutic drugs and toxins

Kimble B, Black LA, Li KM, Valtchev P, Gilchrist S, Gillett A, Higgins DP, Krockenberger MB, Govendir M (2013) Pharmacokinetics of meloxicam in koalas (Phascolarctos cinereus) after intravenous, subcutaneous and oral administration Journal of Veterinary Pharmacology and Therapeutics 36: 486-493 DOI: 10.1111/jvp.12038

Black, LA, Krockenberger, MB, Kimble, B, Govendir, M (2013) Pharmacokinetics of fluconazole following intravenous and oral administration to koalas (Phascolarctos cinereus). Journal of Veterinary Pharmacology and Therapeutics, DOI: 10.1111/jvp.12072.
A study demonstrating the differences in fluconazole pharmacokinetics in koalas compared with other studied species, as well as aspects of its pharmacodynamics when used to treat cryptococcosis.

Black, LA, Landersdorfer, CB, Bulitta, JB, Griffith, JE, Govendir, M (2013) Evaluation of enrofloxacin use in koalas (Phascolarctos cinereus) via population pharmacokinetics and Monte Carlo simulation. Journal of Veterinary Pharmacology and Therapeutics, DOI: 10.1111/jvp.12091.
The only study to use population pharmacokinetic modelling to assess the pharmacokinetics and pharmacodynamics of a therapeutic drug in koalas. This study provides theoretical evidence that enrofloxacin should not be used to treat chlamydiosis in koalas as therapeutic targets are not attained following administration of doses deemed to be safe.

Black LA, McLachlan AJ, Griffith JE, Krockenberger MB, Higgins DP, Govendir M (2013) Pharmacokinetics of chloramphenicol following administration of intravenous and subcutaneous chloramphenicol sodium succinate, and subcutaneous chloramphenicol, to koalas (Phascolarctos cinereus). Journal of Veterinary Pharmacology and Therapeutics 36:478-485. DOI: 10.1111/jvp.12024

Govendir M, Hanger J, Loader JJ, Kimble B, Griffith JE, Black LA, Krockenberger MB, Higgins DP. (2012) Plasma concentrations of chloramphenicol after subcutaneous administration to koalas (Phascolarctos cinereus) with chlamydiosis. Veterinary Pharmacology and Therapeutics. 35 (2):147-54. doi: 10.1111/j.1365-2885.2011.01307.x. Epub 2011 May 16
Two papers presenting pharmacokinetics and clinical reponses to chloramphenicol in koalas with chlamydial disease. Species-specific chlamydial qPCR developed in the study indicates elimination of shedding in most cases over a limited post-treatment period.

Griffith JE, Higgins DP, Li KM, Krockenberger MB, Govendir M. (2010) Absorption of enrofloxacin and marbofloxacin after oral and subcutaneous administration in diseased koalas (Phascolarctos cinereus). Journal of Veterinary Pharmacology & Therapeutics. 33 (6):595-604, doi: 10.1111/j.1365-2885.2010.01169.x
First study of therapeutic drug kinetics in koalas, indicating very low plasma drug concentrations relative to other species

Koala Immunology and Immunogenetics

Maher IE, Griffith JE, Lau Q, Reeves T, Higgins DP (2014) "Expression profiles of the immune genes CD4, CD8β, IFNγ, IL-4, IL-6 and IL-10 in mitogen-stimulated koala lymphocytes (Phascolarctos cinereus) by qRT-PCR." PeerJ (in press)
The development of a suite of assays to allow detailed assessment of the koala immune system for the first time. These methods, long awaited due to the absence of genetic sequence for the koala, revolutionise our abilty to assess the impact of KoRV, toxins, nutrition, stress and disease on the immune system of the koala.

Lau Q, Jobbins S, Belov K, Higgins DP (2013) Characterisation of four major histocompatibility complex class II genes of the koala (Phascolarctos cinereus) Immunogenetics Volume 65 (1): 37-46 doi: 10.1007/s00251-012-0658-5 EPub 2012

Jobbins SE, Sanderson CE, Griffith JE, Krockenberger MB, Belov K, Higgins DP (2012). Diversity of MHC class II DAB1 in the koala (Phascolarctos cinereus) Australian Journal of Zoology 60 (1): 1-9. http://dx.doi.org/10.1071/ZO12013
Two papers characterizing antigen-binding regions of MHCII for ongoing investigation of relationship between host genetic diversity and chlamydial disease in fragmented habitats.

Lau Q, Canfield PJ, Higgins DP (2012) Expression and in vitro upregulation of MHCII in koala lymphocytes. Veterinary Immunology and Immunopathology 147: 35– 43.
First functional study in the koala of expression of MHCII- a key molecule in presentation of antigens to the adaptive immune response. Describes minimal expression of MHCII by stimulated T cells and greater B cell numbers relative to other species, consistent with Th2 predominance; relevant to chlamydial pathogenesis, and one proposed mechanism of KoRV pathogenesis.

Higgins DP, Hemsley S, Canfield PJ (2005) Association of uterine and salpingeal fibrosis with chlamydial hsp60 and hsp10 antigen-specific antibodies in Chlamydia-infected koalas. Clinical and Diagnostic Laboratory Immunology 12(5): 632-639.

Higgins DP, Hemsley S. and Canfield PJ. (2004) Assessment of anti-bovine IL4 and IFN gamma antibodies to label IL4 and IFN gamma in lymphocytes of the koala and brushtail possum. Veterinary Immunology and Immunopathology 101:153-160.
First direct evidence and measurement of IFNg expression in a marsupial. IFNg is a key immune mediator responsible for cellular immunity such as that needed for elimination of chlamydia- the most common infectious disease of the koala.

Koala anatomy and pathology

Hemsley S, Palmer H, Canfield RB, Stewart MEB, Krockenberger MB, Malik R (2013). Computed tomographic anatomy of the nasal cavity, paranasal sinuses and tympanic cavity of the koala. Australian Veterinary Journal 91:353-65