Characterization of the Tacaribe Group of Arboviruses. 1. Propagation and Plaque Assay of Tacaribe Virus in a Line of African Green Monkey Kidney Cells (Vero)

Abstract

An African green monkey kidney cell line (Vero) has been found to support growth of Tacaribe virus. Cytopathic effects (CPE) were pronounced and appeared within 7 days after inoculation with 10-5 dilution of the virus. They were reproducible in 10 serial subcultures. Tacaribe virus also produced distinct plaques with sharp boundaries in monolayer cultures of Vero cells under agar overlay. A linear relationship was observed between plaque counts and virus concentration. The development of CPE and plaques was specifically inhibited by Tacaribe virus immune rabbit serum, but not by Junin or Machupo virus antiserum. Virus assays obtained by titration endpoints of CPE or by plaque counts in tissue culture were comparable to those obtained by titration in suckling mice. When the cultures were infected with <0.001 PFU/cell, virus yields reached their peaks within 7 days.