Cultivation of Mengo encephalomyelitis virus in the embryonated hen egg.

Abstract

SummaryMengo encephalomyelitis (ME) virus was readily propagated in the embryonated hen egg. Infected embryos showed extensive haemorrhages and were usually dead within 48 to 96 hours after inoculation. Sections showed widespread degenerative changes and haemorrhages throughout the entire embryo. The embryo was susceptible to inoculation of ME virus by the amniotic, yolk sac, and allantoic routes and onto the “dropped” chorio-allantoic membrane. After amniotic inoculation, there was a slight lag in virus multiplication, after which rapid multiplication occurred and titers of virus of 10-7 were obtained in suspensions of whole embryos by 48 hours after inoculation. Similar titers were obtained in suspensions of whole embryos and yolk sacs after inoculation by the amniotic or yolk sac routes. The embryo was less susceptible to inoculations by the allantoic route. Irrespective of the route of inoculation, the titer of virus in the allantoic fluids was always less than 10-2 up to 48 hours after inoculation. T...