DIFFERENTIATION BETWEEN MYCOBACTERIUM NONGHROMOGENICUM AND MYCOBACTERIUM TERRAE

Abstract

Mycobacterium nonchromogenicum Tsukamura (1965), M. terrae Wayne (1966), M. novum Tsuka mura (1966), and M. triviale Kubica et al. (1970) are slowly growing, nonphotochromogenic myco bacteria belonging to Runyon's Group III and are isolated from sputum specimens. These are closely related to each other. M. novum is considered as a synonym of M. terrae. It was reported that M. nonchromogenicum and M. terrae are differentiable from each other by nicotinamidase and pyrazinamidase activities and some other properties, but it is also certain that these are very closely related. The purpose of the present study is to search useful characters which are able to differentiate between these two organisms. The results of the present study have shown that the following characters are useful: nicotinamidase, pyrazinamidase, nitrate reduction, heat-stable acid phosphatase, growth at 42°C, and thin-layer chromatography after uptake of ³⁵S-methionine.
M. nonchromogenicum usually grows at 42°C, shows positive heat-stable acid phosphatase activity, and shows a radioactive spot at Rf value 0.94 to 0.98 in thin-layer chromatography. In contrast to the above, M. terrae does not grow at 42°C, does not show heat-stable acid phosphatase activity, and does not show any spot at the Rf value 0.94 to 0.98 in thin-layer chromatography. Usefulness of the heat stable acid phosphatase activity for differentiating these two organisms was shown by Saito et al. This was confirmed by the present study. The other two useful characters, the growth at 42 and the presence or absence of the radioactive spot at the Rf value 0.94 to 0.98, were added in the present study. The substance which shows the spot at the Rf value 0.94 to 0.98 is extracted from bacterial cells by diethyl ether-ethanol