Characterization of Viruses Isolated from Bats

View More View Less
  • Yale Arbovirus Research Unit (YARU), Department of Epidemiology and Public Health, Yale University School of Medicine, 60 College Street, New Haven, Connecticut 06510
Restricted access

Antigenic relations among viruses isolated from bats were studied by complement-fixation, hemagglutination-inhibition, and neutralization testing. This information would help to determine which of these viruses could be identified as strains and which could be recognized as antigenically distinct agents. The viruses were also characterized with respect to their comparative infectiousness for several host systems. Most of the viruses isolated from bats have been previously placed in serogroup B; two were considered ungrouped. The group B viruses included Rio Bravo, Burns, Dakar, BP 180, Ib An 8646, Bukalasa, and Entebbe virus. Antigenic studies indicated that BP 180 and Ib An 8646 were strains of Dakar virus. Bukalasa virus was shown to be closely related to the Dakar virus strains. Rio Bravo and Burns viruses were indistinguishable and were distantly related to MML virus, which, by certain tests, was also distantly related to the Dakar virus strains. The two ungrouped viruses, Kern Canyon and Lagos, were not related to one another nor to any of the other viruses. Plaque formation on LLC-MK2 or Vero cell cultures, or both, and the production of cytopathic effects (CPE) in BHK-21 cell cultures were also studied. Lagos bat and Bukalasa viruses did not produce plaques and Lagos bat virus did not produce CPE in BHK-21 cell cultures. A comparison of the in vitro assays with assays performed in suckling mice indicated that the intracerebral inoculation of suckling mice provided a slightly more sensitive assay system than any of the in vitro systems. Neutralization in LLC-MK2 cell cultures was significantly enhanced by the presence of “fresh” normal serum in the neutralization mixtures, although in certain instances, the enhancement of neutralization was accompanied by a lessening in the specificity of the neutralization reaction.