CHARACTERISTICS OF MURAYAMA VIRUS IN VARIOUS CELL CULTURES AND LABORATORY ANIMALS

Abstract
Some biological properties of Murayama virus, a new paramyxovirus, were studied. The virus grew well in primary monkey kidney cells and in embryonated egg; virus yields in primary chick embryo and BHK-21 [hamster kidney] cells were much lower. The infected BHK-21 cells formed large synctia and showed typical hemadsorption but did not produce any detectable hemagglutinin in the culture fluid. The virus yields were very low in Vero [African green monkey kidney]. LLC-MK2 [rhesus monkey kidney] and MDCK [Madin-Darby canine kidney] cells at 1st passages. The addition of trypsin to the medium enhanced virus growth in Vero and LLC-MK2 but not in MDCK cells. Cell fusion activity of the virus was observed in [human lymphatic leukemia] Molt-4 cells. Hemolytic activity was enhanced by freeze-thawing. Several species of mammals and birds were susceptible to experimental infections with the virus, as evidenced by seroconversion and positive virus isolation; these animals, however, showed no clinical signs.