Abstract
One hundred and twenty-eight of 528 human sera reacted positively with the crude suspension of thiaminase in precipitation reaction. Of these positive 128 sera, 82 sera reacted with thiaminase I, 31 sera with thiaminase II, and 15 sera with the both enzymes. Fourteen strains of Bacillus thiaminolyticus were isolated from the feces of 41 cases whose sera were positive in precipitation reaction with thiaminase I, and 4 strains of Bacillus aneunolyticus from the 14 positive cases with thiaminase II. The human sera that were positive in precipitation reaction inhibited the thiamine decomposing activity of thiaminase.
