title: Evolution of in vitro persistence of two strains of canine parainfluenza virus. Brief report.
abstract: Lytic stock virus (CPI+) exhibited prominent CPE in Vero cell monolayers. The non-syncytial giant cell forming strain (CPI-) was isolated from brain tissues of a dog after experimental infection with syncytial giant cell-forming (CPI+) virus. In mixed infection experiments, CPI(-) virus interfered with the replication of CPI(+) virus in that simultaneously infected cells showed strand-forming CPE typical of CPI(-) and reduction of CPI(+) yield. The CPI(-) virus established immediate in vitro persistence, followed by a severe crisis at passage (p) 8 and several similar crises until p 31; no further crises occurred throughout the remaining observation period (p 80). The CPI(+) did not establish immediate in vitro viral persistence and experienced several lytic crises until p 29. No further crises were observed throughout the observation period (p 100).
mesh_terms: D000818:Animals; D001921:Brain / Q000382:microbiology; D003588:Cytopathogenic Effect, Viral; D004283:Dog Diseases / Q000382:microbiology; D004285:Dogs; D018108:Respirovirus / Q000254:growth & development / Q000472:pathogenicity*; D014466:Ultraviolet Rays; D014709:Vero Cells; D014779:Virus Replication / Q000528:radiation effects