STUDIES OF INFECTIOUS BOVINE RHINOTRACHEITIS VIRUS: 1. PLAQUE ASSAY AND SOME CHARACTERISTICS IN BOVINE KIDNEY CELLS

Abstract
A reproducible plaquing procedure for infectious bovine rhinotracheitis virus (IBRV) in an established bovine kidney cell line is reported. The validity of this system for quantitative analysis has been established by conventional methods.After infection at different multiplicities, one-step growth curves have shown that the eclipse period for IBRV lasts approximately 4 hours and that the infectious virus increases at a logarithmic rate for 12 to 14 hours. The virus yield with the low and high input is 30 PFU and 210 PFU per cell, respectively. Only 1 to 9% of the total virus is released at 24 hours postinfection. The data presented indicate the half-life of IBRV at 37 °C and 42 °C to be 16 and 3.5 hours, respectively. A comparison of hyperimmune bovine and rabbit sera has shown that 92% of the infective particles are neutralized within 30 minutes.