9 May 2001

University of Queensland researchers have discovered a new and unusual organism living in a delicate part of the male koala's anatomy.

The novel bacterium - which appears to be a new genus and species - inhabits the prepuce, or the sac, into which the koala penis withdraws after use.

The UQ researchers have provisionally named and described the bacterium and hope to investigate its potential impact on normal koala reproduction and the further development of artificial insemination programs in this species.

"Mammals have a prepuce in which they store the penis for safekeeping," Dr Steve Johnston said.

"The prepuce contains naturally-occurring bacteria which usually have no ill effects on the male but are still important when preparing semen for storage or artificial insemination."

Dr Johnston, a wildlife reproduction specialist and lecturer in UQ Gatton's School of Animal Studies, was part of the Queensland team which in May 1998 announced the birth of the world's first koala baby, following artificial insemination of its mother.

To get a better idea of the bacterial flora in koala penis sacs, he supplied swabs to the diagnostic bacteriology laboratory in the School of Veterinary Science for further analysis.

Laboratory chief scientific officer Dr Kirsty Townsend said initial findings showed that one particular organism seemed to predominate in all the samples, and its basic traits indicated that it was of the Corynebacterium species.

"However, my predecessor Denise O'Boyle noticed there was something quite different about this organism. After investigation of its fermentation profile, the characteristics did not match those of Corynebacteria normally found in this anatomical region," she said.

Further genetic testing by Veterinary Science/Science student Robin Yates demonstrated it was not a new member of the Corynebacterial group but potentially a new genus and new species, previously undescribed.

This was confirmed through collaborative testing involving Dr Peter Schumann of the German Collection of Microorganisms and Cell Cultures at Jena, Dr Rick Webb of UQ's Centre for Microscopy and Microanalysis and Dr Linda Blackall of UQ's School of Molecular and Microbial Sciences.

"It's an exciting discovery. We think it may be a normal bacterium of the koala prepuce but we don't know its relationship to disease or pathogenicity or in which other mammals it may be present," Dr Townsend said.

"We've done some pilot work searching for the bacterium in virgin female koalas and koala females who have already mated, and have taken a few swabs from other Australian mammals but we would need support to conduct further studies."

The newly discovered bacterium has provided Ms Denise O'Boyle with a most unusual retirement present - and topic of after-dinner conversation - after a 28-year career in the diagnostic bacteriology laboratory. The researchers have provisionally christened it Boylea preputialis in her honour after consulation with latin expert Dr Judith Maitland, University of Western Australia on the correct nomenclature.

The researchers will present their results at the Australian Society for Microbiology conference in Perth from September 30 to October 5.

Media: Further information, Dr Steve Johnston, telephone 07 54 601 076, Dr Kirsty Townsend, 07 3365 3083.