AXENIC GROWTH AND DRUG-SENSITIVITY STUDIES OF BALAMUTHIA-MANDRILLARIS, AN AGENT OF AMEBIC MENINGOENCEPHALITIS IN HUMANS AND OTHER ANIMALS

A cell-free growth medium for the opportunistic pathogenic ameba Balam uthia, mandrillaris is presented. This represents an advance over the use of monkey kidney cells for growth df the amebas and can be helpful in isolation of these amebas from brain tissue from cases in which am ebic meningoencephalitis is a diagnostic possibility, as well as for b iochemical and molecular biological studies. Three isolates of Balamut hia have been cultured in this medium. The cell-free growth system was also used to screen cultures for sensitivity to a variety of antimicr obial agents. Of the various drugs tested, pentamidine isethionate was most effective against amebas (ca. 90% inhibition after 6 days of exp osure), but the drug was amebastatic and not amebacidal in the axenic system at the highest concentration tested (10 mu g/ml).