Viruses of Entamoeba histolytica. VII. Novel beaded virus.

A third amoebal virus type was isolated from four different strains of Entamoeba histolytica. The virus was most frequently seen as a linear structure about 235 nm long and consisting of 14 beadlike structures about 19 nm in diameter. A "dimer" of twice the length and consisting of 28 beads was occationally encountered. The virus replicated in the nucleus, forming ordered arrays. Acridine orange staining of viral aggregates in infected nuclei suggested the presence of double-stranded nucleic acid.