ATTEMPTS OF DIFFERENTIATION BETWEEN MYCOBACTERIUM AND NOCARDIA

Abstract

Nocardia is characterized by its fragmenting impermanent mycelium and weak acid-fastness and Mycobacterium is by its absent or rudimentary mycelium and acid-fastness. However, there occur not rarely strains of these genera which fail to exhibit the characteristics of the genus, and there occur confusions. It is desirable to supplement several biochemical characteristics to the usual morphological characteristics.
We tested five species of nocardia, which were supplied by Dr. I. Uesaka, Kyoto University, according to the schedule of our laboratory for the tests of mycobacteria and compared the characters of nocardia with those of mycobacteria. The results showed that nocardia simulate very much rapidly growing mycobacteria, but a few points for differentiation between these genera could be suggested: two-week-arylsulfatase and utilization of trimethylene diamine as simultaneous sources for nitrogen and carbon. Nitrate reduction also seems to be used as a supplementary one.