Experimental rabies virus infection in Artibeus jamaicensis bats with CVS-24 variants.

An experimental model of rabies was established in the fruit-eating bat species Artibeus jamaicensis. The infections caused by CVS-N2c and CVS-B2c, which are both stable variants of CVS-24, were compared after inoculation of adult bats in the right masseter muscle. CVS-N2c produced neurologic signs of rabies with paresis, ataxia, and inability to fly, while CVS-B2c did not produce neurologic signs. Bats were sacrificed and the distribution of rabies virus antigen was assessed in tissue sections with immunoperoxidase staining. Both viruses spread to the brain stem and bilaterally to the trigeminal ganglia by days 2 to 3. CVS-N2c had disseminated widely in the central nervous system (CNS) by day 4 and had involved the spinal cord, thalamus, cerebellum, and cerebral cortex. CVS-B2c had infected neurons in the spinal cord on day 5 and in the cerebellum, thalamus, and cerebral cortex on day 6. Infected pyramidal neurons of the hippocampus were observed on day 5 in CVS-N2c infection, but infected neurons were never noted in the hippocampus in CVS-B2c infection. CVS-N2c infected many more neurons and more prominently involved neuronal processes than CVS-B2c. CVS-N2c spread more efficiently in the CNS than CVS-B2c. Morphologic changes of apoptosis or biochemical evidence of DNA fragmentation were not observed in neurons with either virus after this route of inoculation. The different neurovirulent properties of these CVS variants in this model were not related to their in vivo ability to induce apoptosis.