Cultivation of Bacillus piliformis (Tyzzer) in mouse fibroblasts (3T3 cells).

Bacillus piliformis was successfully propagated in a continuous mouse-embryo fibroblast cell line (3T3). 3T3 monolayers were successfully inoculated with a variety of infected materials including yolk sac and liver suspensions, minced yolk sac and liver, and primary chicken-embryo liver-cell cultures. An initial decrease in B. piliformis number was noted after inoculation of the cell layer with 2.6 X 10(5) organisms followed by a peak bacterial count at 48 h. Bacillus piliformis remained infectious for mice after 22 passages in 3T3 cell monolayers. Limited growth of B. piliformis was obtained in cell lines of mouse connective-tissue origin (L-929) and mouse liver origin (NCTC 1469).