[The improvement of polyxenic cultivation of Entamoeba histolytica type HK 9]

The serological diagnosis of extraintestinal infections with E. histolytica by indirect immunofluorescence (IFAT) requires a corpuscular antigen. This is produced in our laboratory via polyxenic cultivation of E. histolytica strain HK 9 in a nutrient medium containing a simple salt mixture (Resembling the Ringer-mixture), calf serum and rice starch. It was the aim of the experiments described in this paper to search for a useful medium in which the amebae grow in high density but without substances disturbing the antigen production like debris or rice starch granules. It was shown that the cell culture media of EAGLE MEM and PARKER were easy to handle (contrary to the worldwide used DIAMOND medium TYI-S-33) and brought good results. After a period of 10 subcultures both media were suitable for the cultivation of E. histolytica for making an antigen reasonable for IFAT. As a side effect it was noticed that there was an adaptation phase during which the amebae grew slowly when the medium was changed to another which was completely different (from a cell culture medium to a Ringer-like solution).