Bacteriology and Infectious Diseases

Biography

Biography: Peter Timms

Abstract

Wild koala populations continue to experience serious declines as a result of factors including, (i) loss of habitat, (ii) motor vehicle trauma; (iii) dog attacks; (iv) chlamydial disease. Chlamydial infections have been associated with diseases ranging from ocular disease leading to blindness, as well as urinary and genital tract disease. Modeling shows that targeting chlamydial disease would have the greatest potential impact on stabilising population decline. In the first trial we vaccinated groups of captive healthy koalas via the sc route, using the chlamydial MOMP antigen. We observed good serum and vaginal secretion antibodies as well as specific lymphocyte proliferation responses. In the next trial we utilised a recombinant MOMP protein, cloned from a C.pecorum koala isolate. We vaccinated two groups of koalas, (i) wild caught animals that were clinically healthy and Chlamydia PCR negative, (ii) wild caught animals with no signs of disease. Following vaccination, there was no increase in inflammatory pathological changes in any animals. Strong antibody (including neutralizing antibodies) and lymphocyte proliferation responses occurred in all vaccinated koalas. So far, we have shown that a multi-subunit chlamydial vaccine can be safely administered to both healthy koalas as well as koalas that have a previous or current chlamydial infection. Specific anti-MOMP antibodies are produced at high levels and, importantly, these antibodies are neutralizing in vitro.