A New Virus, “MML,” Enzootic in Bats (Myotis Lucifugus) of Montana

Abstract

Summary A virus related antigenically to the group B arboviruses was isolated from a mouse bitten by a Myotis lucifugus collected in Western Montana, and was subsequently isolated from saliva, brain, and various other tissues of other bats of the same species. The virus produces fatal infection in adult white mice and cavies by intracerebral but not peripheral injection. Suckling mice are susceptible to peripheral inoculation. Rabbits and hamsters are not susceptible upon inoculation into the central nervous system. The virus is readily adaptable to 8-day-old chick embryos inoculated by the amniotic route and to KB cells in tissue culture. The smallest porosity gradacol membrane that permitted passage of the virus was 0.1 µ. It is sensitive to chloroform. Serologic tests indicated affinity but not identity to group B arboviruses: St. Louis, EBSG, Ilhéus, Rio Bravo, and Powassan. Hemagglutination was produced with sucrose-acetone brain antigen at low titer only. Transmission of the virus by the bite of bats and presence of the virus in bat saliva may imply an adaptation of this virus to residence in and transmission by bats without necessary intervention of arthropod vectors. This virus is tentatively designated as Montana Myotis leukoencephalitis (MML) virus.