... replication and virulence.Materials and methods Cells and virusesMadin-Darbycaninekidney(MDCK )cells ,human embryonic kidney cells (293T), mouse kidney epithelial cells (M1), and human lung epithelial cells ... University of Ottawa, Department Of Biochemistry,Microbiology and Immunology. SKD, SW and NEF are PhD students at theUniversity of Ottawa, Department Of Biochemistry, Microbiology and Immunology, ... at 12, 24, 48 and 72 hpi and were assayed foryield of infectious progeny virus as measured by plaqueassay. All the mutants had a significantly increasedability to gr ow in MDCK cells compared...