Isolation of Aino virus from an aborted bovine fetus.

A male fetus of gestation day 187 was aborted from a Holstein-Friesian cow in an epizootic of the Aino virus (AINOV) in September 1995. Neutralizing antibody titers against AINOV were 1:128, 1:16 and 1:64 in the dam serum, fetal ascites and cerebrospinal fluid, respectively. A 10% brain suspension of the aborted fetus was prepared immediately after autopsy, rinsed three times and sonicated before centrifugation. The supernatant was then inoculated into HmLu-1 cell cultures. A cytopathic effect was noted on post-inoculation day 7. The isolated virus was identified as the AINOV based on the physicochemical properties and cross neutralization test. This is the first report on the isolation of AINOV from an aborted bovine fetus.