TOXIGENIC STRAINS OF STACHYBOTRYS-ATRA ASSOCIATED WITH POISONOUS STRAW IN MOROCCO

From 10 moldy straw samples collected in a Moroccan area with an appar ent equine stachybotryotoxicosis outbreak in November 1991, 8 isolates of Stachybotrys atra were obtained. They all showed toxigenesis, howe ver they were variable in nature and intensity. While 1 isolate had on ly mild toxicity when fed to mice as moldy barley, another revealed ve ry high toxicity to Artemia salina larvae, on rat skin, and to mice. T he toxicity of the other 6 isolates were between these 2 limits. This study indicates that the November 1991 outbreak was due to toxigenic s trains of Stachybotrys atra.