Failure of treatment with alpha-difluoromethylornithine against secondary multilocular echinococcosis in mice.

In AKR/J mice inoculated intraperitoneally with protoscoleces of Echinococcus multilocularis, the oral administration of alpha-difluoromethylornithine (DFMO) in drinking water had no obvious effect on the development of hydatid cysts. The DFMO treatment also caused no apparent depletion of three major polyamines (putrescine, spermidine, and spermine) in the cysts, although a slight reduction in the putrescine level was detected. The failure of DFMO treatment to reduce the growth of cysts in mice may result from the absence of ornithine decarboxylase in the parasite.