Conversion of amoscanate to a mutagenic metabolite in gnotobiotic mice implanted with Streptococcus equinus.

Recent in vitro studies indicate that intestinal bacteria convert amoscanate (4-nitro-4'-isothiocyanodiphenylamine), an antischistosomal drug, to a potent mutagen. The present study indicates that the implantation of germfree mice with Streptococcus equinus, isolated from the small intestine of conventional mice, restores the mutagenic activation of amoscanate in vivo.