MENINGOENCEPHALITIS IN A KOALA (PHASCOLARCTOS-CINEREUS) DUE TO CRYPTOCOCCUS-NEOFORMANS VAR GATTII INFECTION

A 10-yr-old male captive koala (Phascolarctos cinereus) was examined f or neurologic signs. The animal had a stress leukogram and a hypoalbum inemia. Cerebrospinal fluid analysis revealed inflammatory disease due to yeasts, which on subsequent culture and biotyping proved to be Cry ptococcus neoformans var. gattii. A latex-cryptococcal antigen test (L CAT) on serum gave a high titer of 1:512. At necropsy the koala had an extensive meningoencephalitis and focal pneumonia due to cryptococcal organisms. Cryptococcosis has been recorded in koalas before, but bio typing has not been attempted. In this koala, the source of the organi sm appeared to be forest red gums (Eucalyptus tereticornis), and it wa s speculated that the animal was predisposed by immunosuppression, pos sibly triggered by altered management practices.