Abstract
A method for in vitro serial passage cultivation of T. muris was studied and the results obtained are as follows. (1) In three well known media (Tanabe-Chiba [15], Cysteine-Peptone-Liver Infusion-Maltose (CPLM) [10] and Egg-York Liver extract (Balamuth) [1, 2]) the trophozoites disappeared within 24 hrs. In Trypticase-Yeast-Maltose (TYM) [7] medium, they remained viable for 6 days but disappeared gradually within 4 successive passages. (2) In an autoclaved modified TYM, in which mouse cecal extract was added in all ingredients of TYM, the trophozoites could develop for 72 days (36 passages). (3) The isolation of trophozoites from cecal material was carried out by the method of gradient centrifugation with a Ficol-Conray 800 solution. By this technique, many viable trophozoites could be isolated. (4) Some of the trophozoites cultured for 72 days were frozen in liquid N2 and proved viable after 14 days storage. These trophozoites could be cultured in the autoclaved modified TYM for more than One year.
