Treatment with agmatine inhibits Cryptosporidium parvum infection in infant mice

Cryptosporidum parvum is an intracellular protozoan parasite that causes en teric infection and diarrhea in a wide range of mammalian hosts, including humans and economically important livestock species. There are no effective vaccines or drug treatments available for cryptosporidiosis. Cryptosporidi um parvum utilizes a unique metabolic pathway for the synthesis of polyamin es, forming agmatine as an intermediary metabolite. We treated infant mice with oral doses of agmatine for 2 days before, the day of, and 5 days follo wing experimental infection with C. parvum. Mice treated with agmatine were significantly less infected with C. parvum than were control mice receivin g phosphate-buffered saline. Mice treated with agmatine only on the day of experimental infection with C. parvum were also significantly less infected than were control mice. These data suggest that exogenous agmatine alters the metabolism of C. parvum sufficient to interfere with its ability to col onize the mammalian intestine.