Growth Profiles of Recent Canine Distemper Isolates on Vero Cells Expressing Canine Signalling Lymphocyte Activation Molecule (SLAM)

Fresh samples of lymph node, lung and cerebrum taken post mortem from dogs no. 1, 2 and 3 yielded canine distemper virus (CDV) strains 007 Lm, 009 L and 011 C, respectively. These were titrated on Vero cells stably expressing canine signalling lymphocyte activation molecule (SLAM; Vero-DST cells). Growth curves of the three strains were produced by titration of the released virus and cell-associated virus at various timepoints. All three isolates, especially 007 Lm, grew well on Vero-DST cells. The titres of cell-associated virus of two strains (009 L and 011 C) were clearly lower than those of virus released into the culture supernate. The results indicate that Vero-DST cells are not only useful for primary isolation but also efficient for titrating virus from fresh tissues and for the study of growth profiles of recent CDV isolates.