Abstract

In this study, we examined clinical specimens obtained from 564 patients with suspected tuberculosis and cultured with BACTEC 460 TB system in the Black Sea Technical University Clinical Microbiology Laboratory between 1998-2004. Using the same system, drug-susceptibility tests for isoniazid (INH), rifampicin (RIF), streptomycin (SM) and ethambutol (EMB) were preformed in 442 culture positive specimens and the resistance rates were found to be 24.6%, 15.8%, 9.9% and 18.8%, respectively. The rate of resistance to both INH and RIF, referred as multidrug resistance was 14.7% (65/442), and the highest multidrug resistance rate was determined in 1999 (19.6%). While a Mycobacterium tuberculosis strain from a patient was sensitive to RIF and EMB, after one year it became resistant to both drugs. Since high rates of combined drug resistance is the indication of the dimension of primary resistance in the future, it seems to be important to prevent inappropriate anti-tuberculous drug prescription, to perform drug susceptibility tests regularly and also to examine the distribution of resistant strains.