Microsporidia (Encephalitozoon cuniculi) in wild rabbits in Australia

Abstract

OBJECTIVE: To determine the prevalence of infection with Encephalitozoon cuniculi in wild rabbit populations in Western Australia, and to isolate the organism from seropositive rabbits. DESIGN: Serological screening of wild and clinically affected domestic rabbit populations. SAMPLE POPULATION: Eighty-one wild rabbits from south-western Western Australia and 29 laboratory rabbits. PROCEDURE: Indirect immunofluorescence antibody technique and in-vitro amplification of parasite isolates in fibroblast cultures. RESULTS: Of the 81 wild rabbits and 29 laboratory rabbits, 20 and 22 respectively, had antibodies to E cuniculi. E cuniculi from the urine of one seropositive laboratory rabbit and from brain and kidney tissues of eight and five seropositive laboratory and wild rabbits respectively were isolated in fibroblast cultures. CONCLUSION: E cuniculi infection has been shown for the first time to be prevalent in wild rabbits in Australia. Techniques have been developed for the isolation and culture of the causative agent. Comparative studies can now be undertaken to determine risk factors for clinical disease in domestic rabbits and the relationship among E cuniculi isolates from wild and domestic rabbits.