Experimental zygomycosis in rabbits: Clinicopathological studies

Zygomycosis was produced experimentally in 20 New Zealand white rabbits ( O ryctolagus cuniculus) by intra-nasal administration of spores of Absidia co rymbifera. Infected animals showed dullness, depression, coughing and mucop urulent nasal discharge, but no mortality. Haematology revealed no signific ant change in Hb and PCV, but leukocytosis due to neutrophilia in the initi al stages of the experiment. There was a significant increase in serum tota l proteins, creatinine, AST, ALT, total Igs and CICs. A. corymbifera specif ic IgM and IgG antibodies were detected in the sera of the infected animals . Gross lesions consisted of pneumonic consolidations of the antero-ventral lobes of the lungs. Microscopically, histology showed formation of pyogran ulommas in the lungs. Fungal elements typical of A. corymbifera were demons trated in the tissues upto 15 days after infection by special stains and co nfirmed by indirect immunoperoxidase. Re-isolation of the fungus from lungs was also achieved consistently upto 15 days only. It was concluded that in tra-nasal instillation of A. corymbifera in rabbits produced significant cl inico-pathological alterations with the lesions confined mainly to the lung s. In the present study, neither systemic dissemination of the disease occu rred nor were kidneys site of predilection as reported earlier.