[Resistance rates of Mycobacterium tuberculosis complex strains isolated from clinical specimens]

The aim of this study was to investigate isoniazid, rifampicin, streptomycin and ethambutol resistance rates of Mycobacterium tuberculosis complex strains isolated from clinical specimens in the Mycobacteriology Laboratories of Karadeniz Technical University Hospital between January 2005-March 2010. A total of 212 M.tuberculosis complex strains, 152 (71.7%) of which were isolated from respiratory specimens and 60 (28.3%) from non-respiratory system specimens, were included to the study. M.tuberculosis complex strains were determined by polymerase chain reaction using primers specific for the IS6110 gene region. Single isolate of each patient were enrolled in the study. Antituberculosis drug susceptibility testing was performed by BACTEC MGIT 960 (Becton Dickinson, USA). Of the 212 isolates, 157 (74.05%) were susceptible to all of the four antimycobacterial agents while 55 (25.9%) were found resistant to one or more of the drugs. The monodrug resistance rates were found as 6.1% for isoniazid, 0.5% for rifampicin, 5.2% for streptomycin, and 2.4% for ethambutol. The number of multidrug resistant isolates characterized with resistance to isoniazid and rifampicin were 10 (4.8%). Our findings indicated that the rates of mono and multidrug resistant M.tuberculosis complex strains were significantly lower than the rates previously reported from our region and similar to the average country-base resistance rates reported by the Ministry of Health. Continuous monitoring of M.tuberculosis antimicrobial resistance at regional level would greatly aid to the success of the tuberculosis surveillance program in Turkey.