DETECTION OF FELINE CORONAVIRUSES BY CULTURE AND REVERSE TRANSCRIPTASE-POLYMERASE CHAIN-REACTION OF BLOOD-SAMPLES FROM HEALTHY CATS AND CATS WITH CLINICAL FELINE INFECTIOUS PERITONITIS

A reverse transcriptase-polymerase chain reaction (RT-PCR) assay for t he detection of the feline coronavirus (FCoV) genome and a co-cultivat ion method for the isolation of field strains of FCoV are described. U sing the RT-PCR assay to assess blood samples from cats with feline in fectious peritonitis (FIP) (n=47) and healthy cats from households wit h endemic FCoV (n=69) it was shown that approximately 80% of the cats were viraemic, irrespective of their health status. It was also shown that, over a 12-month period, a similar percentage of healthy cats rem ained viraemic, and that the presence of viraemia did not appear to pr edispose the cats to the development of FIP. The co-cultivation system proved to be a suitable method for the culture of field strains of FC oV from blood samples, so long as the cultures were maintained for at least 4 weeks. Using this system, followed by the RT-PCR, viraemia was detected as frequently as by RT-PCR on RNA extracted directly from pe ripheral blood mononuclear cells. (C) 1998 Elsevier Science B.V. All r ights reserved.