Inhibition of Multiplication in Acanthamoeba castellanii by Specific Inhibitors of Ornithine Decarboxylase1

Abstract

Proliferation of Acanthamoeba castellanii (Neff strain) in either a broth medium or a defined medium was arrested by .alpha.-monofluoromethyldehydroornithine(.DELTA.-MFMOme), .alpha.-difluoromethylornithine (DFMO), and (R,R'')-.delta.-methyl-.alpha.-acetylenic putrescine (MAP), three specific inhibitors of ornithine decarboxylase. Although all three inhibited the ameba enzyme, .DELTA.-MFMOme was the most effective inhibitor of multiplication. Growth inhibition was reversed by the addition of polyamines. The inhibitors did not induce differentiation by themselves although DFMO caused encystment when supplemented with CaCl2 or MgSO4.