Note on the Transfer of Strains of Entamoeba Histolytica from One Bacterial Flora to Another

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  • Department of Microbiology and Public Health, The Chicago Medical School, Chicago 12, Illinois

Certain experiments have recently been designed in which it was desirable to transfer specific strains of Entamoeba histolytica from the Shaffer-Frye (S-F) medium to a diphasic medium with the mixed bacterial flora of another strain of E. histolytica. In order to accomplish this it was necessary to separate the particular flora to be used from its accompanying strain of amebas. It was routine practice to take a loopful (4 mm.) of inoculum from the top of the fluid column of the culture of E. histolytica in diphasic medium and transfer it to a similar medium. Since the multiplication of the amebas in such a culture occurs in the bottom of the fluid phase, it seemed unlikely that any amebas would be carried over with a loop transfer taken from the top. It was therefore surprising to find that in a high per cent of such transfers E. histolytica was present when the cultures were examined after 24 to 48 hours incubation at 37° C.