Abstract
Recently in the United States several cases are reported on the simulation of pulmonary tuberculosis by atypical acid-fast bacilli and numerous studies have been made on the characteristics of such strains.
During our daily business, we believe it doubtful whether it is adequate to name these non-tuberculous bacilli same as atypical acid-fast bacilli or yellow bacilli. Due to the fact that in nature non-pathogenic acid-fast bacilli are widely distributed and also these bacilli are often found in our laboratory from the various kinds of speciments, we believe we should differentiate it with utmost care.
In purpose of studying the chromogenic acid-fast bacilli on Qgawa's egg culture medium we have investigated 17 strains isolated since 1955.
1) Isolation frequency; The frequency of happening isolation from the specimens were as follow:
(1) Sputum-12 out of 2, 142 cases (0.56%).
(2) Urine-3 out of 158 cases (1.9%).
(3) Gastric lavage and others- (0) out of 196 cases.
2) Character of colonies and morphology of cells: The colonies of almost all the strains were yellow or orange in color and smooth, soft and creamy in form. Their viscosity were found to be strong, however, they were easily homogenized into smooth cell suspensions. Morphologically, most of them resembled the human typed tubercle bacilli and some did not. In general, they were polymorphylic.
3) Preis test: Almost all the strains had decolouration in less than 2 minute's boiling.
4) Anti-alkaline test: Viability was not lost after treatment with 4% NaOH solution for one hour.
5) Influence of light on chromogenesis: Pigmented colonies grew either in the dark or in the light. In other words, they were all scotochromogens.
6) Sensitivity test for anti-tuberculous substances: All of the strains displayed resistance toward SM, PAS and INH with some difference in degree.
7) Neutral red test: All were found to be negative with neutral red test by Hughes method.
