Incidence of typical and atypical mycobacteria in pulmonary infections at Lahore--a study of 500 cases.

Five hundred sputum samples of clinically diagnosed or suspected tuberculous patients were subjected for the isolation of mycobacteria. Of these 239 (47.8 percent) were culture positive and 204 (40.8 percent) smear positive. Of the smear positive specimens 39 (7.8 percent) could not propagate on Lowenstein jensen medium. From total isolates, 235 strains were of Myco. tuberculosis and remaining four were atypical type. The atypical strains were classified on the basis of Runyon’s classification. Two strains were of Myco. serofulaceurn: Group II, one Myco. intracellulare: Group III, and one Myco. smegmatis: Group IV. On animal pathogenicity test and Myco. serofulaceum less pathogenic for guinae lulare (Battey bacilli) was very low, whereas Myco.smegmatis did not cause any lesions or disease (JPMA) 34 : 84, 1984).