Isolation and identification of a novel feline coronavirus from a kitten with naturally occurring feline infectious peritonitis in Taiwan.

Feline infectious peritonitis (FIP) is a chronically progressive and usually fatal disease caused by feline coronavirus (FCoV). Only few virus strains were documented around the world; the latest FCoV strain was an isolate obtained nearly twenty years ago. By co-cultivation of pleural effusion from a 4.5-month-old FIP kitten with feline fcwf-4 cells, a local FCoV was isolated. Multinucleated cells, a typical coronavirus induced cytopathic effect (CPE), were readily observed after three days of co-cultivation. Viral antigen was confirmed by immunostaining and the virus was identified as a type II FCoV through genotyping. A replication cycle less than 6 hours, shorter than any other FCoV reference strains, was noted. Among the two feline cell lines that were reported to propagate type II FCoV, only fcwf-4 cells appear to support the growth of our isolate efficiently. This novel FCoV isolate with distinct growth characteristics is denominated as FCoV/NTU156/P/07 (NTU156), the first FCcV strain in Taiwan.