Multidrug-Resistant Tuberculosis in the Czech Republic(1999–2001)

Overview

Background.
Multidrug-resistant (MDR) tuberculosis, defined as a disease caused by Mycobacterium tuberculosisstrains,which are resistant tomore antituberculous drugs (at least to isoniazid and rifampicin), is a problemfrequentlydiscussed in the Czech Republic. Cases of specific disease refractive to causal antituberculous therapy are associatedwith the risk of the spread of the causative agent among the population.Methods and Results. The National Reference Laboratory for Mycobacteria collected 2813 Mycobacteriumtuberculosis strains isolated by Czech mycobacteriological laboratories in 1999 to 2001. All strains were tested forsusceptibility to basic antituberculous drugs and then theMDR strains were further tested for susceptibility/resistanceto other antituberculous and antibacterial drugs. TheMDR strainswere studied byDNAanalysis (DNAfingerprintingrestriction analysis, RFLP – Restriction Fragment Length Polymorfism) as well. Thirty-nine patients who had MDRtuberculosis were excretors of 56 Mycobacterium tuberculosis strains. In average, MDR tuberculosis accounted for1.96 % (1,7–2,4) of all cases of bacillary tuberculosis. The most frequent type of the multidrug resistance was thatresistant to four basic antituberculous drugs (isoniazid, rifampicin, ethambutol and streptomycin). It was confirmedin 48.2 % multidrug resistant strains.Conclusions. Isepamicin, clofazimin, capreomycin and amikacin are considered to be the most promising antituberculosisdrugs. Based on RFLP profiles, 61.5 % of strains were placed into 8 clusters while the other strainsremained unclustered. No significant differences in geographical distribution and population structure were foundbetween the excretors of clustered strains and those of unclustered strains. Preliminary comparison with restrictionprofiles of the MDR Mycobacterium tuberculosis strains in the international database suggests the uniqueness ofCzech strains showing the profiles not found elsewhere to date.

Key words:
Mycobacterium tuberculosis, multidrug-resistant tuberculosis (MDR TB), susceptibility testing, antituberculousdrugs, Restriction Fragment Length Polymorphism (RFLP).