Chlamydial Disease of the Koala: A Study of Pathogenesis and Host Response

Abstract

Chlamydial infection occurs commonly in koalas (Phascolarctos cinereus) and, as in humans, can cause proliferative conjunctivitis and disease of the urinary and reproductive tracts. Past studies suggest that increased expression of chlamydial disease in koalas is associated with habitats disturbed by humans, but the mechanisms and specific factors influencing susceptibility of koalas to disease have not been studied in detail. This thesis aims to further the goal of describing pathogenic mechanisms and the host-pathogen-environment interaction for chlamydial disease in koalas by developing techniques to begin exploring in koalas some of the concepts that are central to our understanding of this condition in humans. These concepts include the role of T helper 1 (Thl)/ T helper 2 (Th2) lymphocyte balance and interferon gamma, and the association of reproductive tract fibrosis and infertility with serological responses to chlamydial heat shock proteins.