Isolation and identification of aujeszky's disease virus from outbreaks in swine in the state of santa catarina brazil
Rowe, C.A.; Romero, C.H.
Pesquisa Veterinaria Brasileira 6(3): 99-103
ISSN/ISBN: 0100-736X Accession: 005764782
From April 1983, through December 1985, 18 isolations of Aujeszky's disease virus (ADV) were made in the State of Santa Cartarina, Brazil, from the brains of piglets (17 samples) and a dog, all of which had shown nervous symptoms. All viruses were isolated either in primary cultures of chicken embryo fibroblasts or in a swine kidney cell line. Identification of the isolated agents was made both by direct immunofluorescence (IF) on coverslips and by virus neutralization (VN) in microplates, using reference serum specific for ADV. All 18 isolates induced a cytopathic effect (CPE) typical of herpesvirus, first noticeable 24 hours after inoculation and characterized by the rounding up and high refractiveness of affected cells. Direct IF demonstrated intense fluorescence of the entire cell monolayer in cultures in cultures inoculated with 10% and 1% brain suspensions, while 0.1% suspensions allowed the formation and visualization of bright fluorescent plaques amidst dark areas of uninfected cells. The presence of ADV was also confirmed in the VN test using the third passage of each of the 18 isolates. Characteristic herpesvirus CPE was observed in cultures inoculated with mixtures of the isolates and negative reference serum, while no CPE was seen in cultures inoculated with mixtures of the isolates and positive reference serum. Extracts prepared from the cell fraction and from the fluids of infected cultures contained two antigens that were demonstrable in the immunodiffusion test. Similar extracts prepared from uninfected cultures did not contain these antigens.