EXPERIMENTS WITH GROWTH OF THE EEL TRYPANOSOME, TRYPANOSOMA-GRANULOSUM LAVERAN AND MESNIL, 1902, IN SEMI-DEFINED AND DEFINED MEDIA

Growth of the eel trypanosome, Trypanosoma granulosum, was attempted i n five semidefined and three defined media. Growth was poor in four se mi-defined and two defined media, but one semi-defined medium, a modif ied version of SDM-79 without MEM F-14, supported good growth of the t rypanosome. In this medium, doubling time was between 1 and 2 days, ov er 90% of organisms seen in culture after 6 days were trypomastigotes, and 1.8 + 0.1 x 10(7) trypanosomes ml(-1) was achieved in 7 days. Whe n foetal calf serum from the modified SDM-79 was substituted with insu lin to create a fully defined medium, a modest but significant increas e in cell numbers occurred compared with controls. In vitro experiment s with D, L-alpha-difluoromethylornithine (DFMO) showed morphological changes leading to destruction of the trypanosome with increasing conc entrations of the drug. A 50-mM concentration of DFMO inhibited growth by more than 90%, and the IC50 was found to be 16 +/- 2 mM.