Arylsulfatase activity for differentiating Mycobacterium avium and Mycobacterium intracellulare

Arylsulfatase activities (96-h reaction) of various strains of Mycobacterium avium and M. intracellulare, as identified by a DNA probe test, were measured. The enzyme activities of M. avium strains were significantly lower [corrected] than those of M. intracellulare strains (P less than 0.005 to P less than 0.025). The enzyme activities did not vary with serovar; that is, the activities of serovars 1, 2, 8, and 9 (belonging to M. avium) were similar to each other, as were the activities of serovars 7, 12, 13, 14, and 16 (belonging to M. intracellulare). The results indicate the usefulness of the arylsulfatase test in distinguishing M. avium from M. intracellulare in an accurate manner.