Growth characteristics of canine pathogenic viruses in MDCK cells cultured in RPMI 1640 medium without animal protein

Madin Darby canine kidney (MDCK) cells were adapted to serum-free RPMI 1640 medium and used for cultivation of canine viruses. RPMI 1640 medium was supplemented with a soybean peptone, l-glutamine and antibiotics, so that the protein concentration was less than 5 μg/ml (RPMI/SP medium). The resulting adapted MDCK-SP cells showed steady growth after the twenty-eighth passage in RPMI/SP medium (MDCK-SP cell culture). Canine distemper virus, canine parvovirus, canine adenoviruses and canine parainfluenza virus, which are the principal components of canine combined virus vaccines, grew in the MDCK-SP cell culture as efficiently as the parental MDCK cells cultured in the conventional Eagle's MEM containing fetal bovine serum. Consequently, the use of MDCK-SP cell culture can make current canine vaccine products much safer, of higher quality and at lower cost.