Development of a chlamydial vaccine for koalas (Phascolarctos cinereus) 

Shahneaz Ali Khan

Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia 

ABSTRACT

The koala (Phascolarctos cinereus) is an iconic arboreal marsupial and the only surviving member of the Family Phascolarctidae. Chlamydiosis in koalas causes significant morbidity and mortality and adds to the detrimental effects of anthropological changes such as deforestation, bush fire, motor vehicle trauma and dog attacks. Mathematical modelling suggests that by reducing the negative effects of chlamydiosis, koala population in decline could well be saved. Chlamydia is an obligate intracellular pathogen of both humans and animals and C.pecorum is the most common and serious species affecting koalas. Ocular infections in koalas cause kerato-conjunctivitis leading to blindness, whereas uro-genital infections cause thickening of the bladder wall, incontinence and fibrosis in the uterine tract. While antibiotics are the current leading curative measures, these are ineffective for severe chlamydiosis and can also affect the intestinal micro flora and the overall health of the animals. The asymptomatic nature of the chlamydial infection and the variable effects of the long term antibiotic treatment heighten the importance of developing a suitable anti chlamydial vaccine.