Change in biochemical and biological characteristics of Mycobacterium tuberculosis strains isolated in recent years

: One hundred strains of Mycobacterium tuberculosis isolated in 1988-89 from patients who were newly hospitalized in the National Chubu Hospital were studied on their biochemical and biological characteristics and compared with the strains isolated previously. Recently isolated strains showed frequently a much stronger arylsulfatase activity, grew at a higher rate at 42 degrees C, and showed a little stronger niacin production.