FURTHER-STUDIES OF NATURALLY-OCCURRING LATENT BOVINE HERPESVIRUS-INFECTION

Abstract

Attempts were made to enhance the isolation rate of latent bovine herpesviruses from trigeminal ganglia by using a fibroblastic fetal bovine kidney cell line, in addition to Madin-Darby bovine kidney cells, and by superinfecting with a temperature-sensitive helper strain of bovine herpesvirus-1 (BHV-1). Four isolates of latent BHV-1 were obtained from 44 pairs of trigeminal ganglia, thus reflecting no increase in isolation rate over that previously observed. Two isolates of a latent bovine herpesvirus indistinguishable from BHV-3 strain DN599 were also obtained. Analysis of plaque morphology of BAV-1 isolates obtained in this and a previous study indicated that several biologically heterogeneous strains were capable of establishing latent infections.