Preliminary studies on feline coronavirus distribution in naturally and experimentally infected cats

The shedding, tissue distribution and quasispecies composition of feline co ronaviruses were studied in naturally and experimentally infected cats. The infection remained subclinical, but the majority of the animals shed the v irus via faeces throughout the experiment. Sequences corresponding to the v iral nucleocapsid region were amplified by reverse-transcription polymerase chain reaction from the cortex, dura mater, pancreas, lungs, third eyelid, and the heart muscle in four cases. Interestingly, the ORF7b viral region - a supposed virulence factor - was detected in fewer organs, raising the p ossibility that this region can be affected by deletions during virus repli cation in vivo. It is demonstrated that the composition of the viral quasispecies differs b etween organs, and that genomic regions with different functions undergo di stinct processes of selection, which should be considered during the evolut ion of feline coronaviruses.