The origin and pathogenicity of Basidiobolus species in northern Australia

Basidiobolus haptosporus Drechsler causes human and animal disease in the tropics. This paper reports the isolation of this organism from natural substrates and describes the pathogenicity of the isolates. Basidiobolus was recovered from faecal samples of amphibians, reptiles and macropods, from woodlice, and from granulomatous skin lesions of horses. Some isolates were heat-tolerant. Almost all of the heat-tolerant isolates were pathogenic to suckling mice and had smooth or undulate, or smooth plus undulate zygospore walls. When inoculated intracerebrally into suckling mice they caused encephalomalacia, necrosis, meningoencephalitis, congestion, haemorrhage and a granulomatous reaction in the central nervous tissue, hydrocephalus and nervous signs. There was a variety of animal sources of pathogenic strains of the organism which were widely distributed in the sampling area, thus the potential hazard of infection could be more serious than previously considered.