Isolation of Basidiobolus ranarum from ectotherms in Antwerp zoo with special reference to characterization of the isolated strains

Ten Basidiobolus ranarum (=Basidiobolus haptosporus) strains, isolated from faeces of 102 different lower vertebrates (ectotherms) exhibited in Antwerp Zoo, or from their environment were studied for their temperature requirements, haemolysis and other enzyme activities in vitro. All isolates grew well at 25 and 37 °C. Three strains that produced undulated zygospore walls were haemolytic and positive for hyaluronidase. All the isolates produced urease, N-acetyl-β-glucosaminidase, trypsin, lipase, lecithinase, gelatinase, collagenase and elastase, but failed to produce amylase, keratinase and β-glucosidase. Three isolates failed to produce phosphatase. Only one strain failed to produce DNase. Aesculin was not hydrolysed. Chitinase activity was inconclusive. The results of this study illustrate the importance of exotic animals kept in temperate regions as carriers of potentially pathogenic organisms. In addition to the morphological characteristics, the identification can be based on enzymatic profiles. Enzymatic activity detection may help to explain the pathogenic mechanism of the fungus.