Multidrug-resistant tuberculosis in Russia: clinical characteristics, analysis of second-line drug resistance and development of standardized therapy

The aim of the study presented here was to identify patients with multidrug resistant tuberculosis (MDRTB) in the Samara region of Russia and to analyze the susceptibility of their isolates to second-line drugs in order to develop an empirical, standard, second-line treatment regimen. Treatment of MDRTB can be individualized based on in vitro laboratory analysis or standardized. In the latter case there is still a need to ascertain local second-line drug-resistance patterns. Described here are the clinical characteristics of 251 MDRTB patients identified in the study and the second-line drug susceptibility of 69 MDRTB isolates obtained from them. Antimicrobial resistance to the following agents was detected in the isolates: rifabutin (88.2%), streptomycin (42.8%), amikacin (7.2%), doxycycline (7.4%), ciprofloxacin (4.3%), clofazimine (2.9%), cycloserine (7.4%), and prothionamide (1.5%). The results of the study indicate it is possible to develop a standard, effective, clinical treatment regimen using ethambutol, pyrazinamide, prothionamide, a fluoroquinolone and amikacin.