Studies on Identification and Drug Resistance of Atypical Mycobacteria Isolated from Patients with Pulmonary Tuberculosis

Abstract

The differential diagnosis of atypical mycobacteriosis caused by atypical mycobacteria (with the exception of Mycobacterium tuberculosis, Mycobacterium bovis, and Mycobacterium leprae) which are widly distributed in soil and water, from pulmonary tuberculosis is possible only when atypical mycobacteria are isolated and identified. In this investigation, attempts were made to isolate atypical mycobacteria from persons registered as tuberculosis patients in the Anyang Health Center in Anyang City, Kyungki province, Korea. Biological and biochemical tests were performed for the atypical mycobacteria isolated from these patients, also retrospective analysis of clinical and X-ray findings of the patients with bacteriologically confirmed atypical mycobacteriosis were done. The results can be summarized as follows: 1. 103 strains of mycobacteria were isolated among 334 sputum samples from patients. 2. Among the isolated mycobacteria, 10 strains (9.7%) were found to be a atypical mycobacteria and 93 strains (90.3%) were tubercle bacilli of human type. 3. On the basis of Runyon's grouping of atypical mycobacteria, there were 3 strains (30.0 %) of scotochromogen and nonphotochromogen respectively, 4 strains (40.0%) of rapid grower, and no photochromogen. 4. By biochemical tests, 3 strains of scotochromogen were identified as Mycobacterium scrofulaceum (2 strains) and Mycobacterium szulgai (1 strain) 3 strains of nonphotochromogen were Mycobacterium avium-complex (2 strains) and Mycobacterium terriae (1 strain), and 4 strains of rapid grower were Mycobacterium fortuitum (3 strains) and Mycobacterium chelonei. 5. In drug sensitivity tests, all 10 strains isolated atypical mycobacteria showed resistance to various concentration of INH and SM and low concentration (10mcg, 40mcg and 50mcg) of EB, TH, and CS, and were sensitive to only high concentration (20mcg and 100mcg) of EB, TH, CS, and RFP. 6. In analysis of clical findings by the patients with bacteriologically confirmed atypical mycobacteriosis, it was found that clinical symptoms of these patients appeared not to be mild than those of patients with pulmonary tuberculosis. The patients with atypical mycobacteriosis had been treated for pulmonary tuberculosis for a long time and they showed no improvement.