The identification of tubercle bacilli from skin lesions is required to make a definite
diagnosis of skin tuberculosis. However, not only are clinical lesions quite variable, but
also the amount of acid fast organisms contained in such lesions is so small that the
identification of tubercle bacilli from these tesions has been found a matter of difficulty
(Nguyen, 1973; Yamauchi, Klein, and Farrell 1973, Smith, Ryan, Sanderson and Sarkany
1976). In the present study, the isolation and identification of acid fast organisms from
suspected skip tuberculosis cases was attempted by employing the Korean
chipmunk(Eutamisa sibiricus asiaticus) as an experimental animal, as these animals have
been reported to be susceptible to various acrid fast organisms, including tubercle bacilli
(Chang, Lew and Choi 1971 ; Choi, Lew Kim, Kim and Pyull 1972; Kang and Lew 1976)
The following is a summary of the findings in this study.
1. There were no acid fast organisms detected in any of the materials which were
prepared by direct and concentration smears of the lesions of 17 suspects. Two strains
of acid fast organisms were isolated from the lesions of skin tuberculosis after culturing
them for one week in vitro. By the chipmunk inoculation method,: two strains were
isolated from the lesions at the 3rd and 4th weeks after inoculation.
2. In physicochemical analysis of the above 4 strains, 2 from in vitro culture and 2 from
chipmunk inoculation, the 2 strains from the chipmunk inoculation were identified as
Mycobacterium tuberculosis and the 2 strains from in vitro culture were identified as
rapid growers, both of them being atypical acid fast organisms. The two strains of
Mycobacterium tuberculosis were isolated from 2 patients who were preliminarily
diagnosed as having Lupus vulgaris. Mycobacterium fortuitum was isolated from a case
of Erythema induratum and the other unidentified atypical mycobacterium from a patient
with Lupus erythematosus.
3. The susceptibility of the 4 isolated strains of mycobacteria to the primary
antituberculcsis drugs was also tested in vitro. The two strains of for Mycobacterium
tuberculosis were found to be susceptible to 10-100 μg/ml of PAS and SM. The
Mycobacterium fortuitum showed resistance to all of the drugs tested. The unidentified
rapid grower demonstrated susceptibility to PAS and SM at a concentration of 100μ
g/m1. As a final summary, a total of 4 strains of acid fast organisms, 2 from cultures
and 2 from chipmunk inoculation, were successfully isolated. Therefore, the Korean
chipmunk is recommended as an experimental animal for the identification of acid fast
organisms obtained from suspected skin tuberculosis patients. However, the 2 strains
clef atypical acid fast organisms isolated from the culture were not detected in the
inoculated chipmunks. Thus, it is still necessary to study further the question of
whether or not chipmunk inoculation alone can provide a satisfactory method for the
identification of atypical mycobacteria from skin tuberculosis.
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