Cultivation of Cowdria ruminantium in bovine vascular endothelial cells

The organism had previously been grown only in bovine umbilical cells. Two Zimbabwean isolates of C. ruminantium (Crystal Springs, Palm River) as well as one from South Africa (Welgevonden), were repeatedly isolated from animal sources in one or more of the vascular cell line tested. Repeated serial passage of the Crystal Springs and Welgevonden isolates was obtained in 3 of the 4 lines. The organism was infective for sheep after in vitro growth and extracellular elementary bodies or from infected cell cultures fluoresced brightly through the 1: 1250 dilution of immune bovine serum. This fluorescence was absent from higher dilutions of serum and cell controls. (Author abstract)