Abstract
Introduction: Multidrug resistant tuberculosis (MDR-TB) is a severe threat to effective TB-control as well as to successful treatment of the individual patients. The reported incidence of MDR-TB in Belarus is somewhat lower than in its neighboring countries, but the level of MDR-TB causes severe obstacles for the national TB program.
Objective: To characterize MDR-TB and pan-susceptible M tuberculosis clinical isolates from TB patients in Belarus by molecular strain typing.
Methods: The study totally comprised 163 clinical isolates from patients with pulmonary TB in Belarus, 81 isolates being MDR and 82 being pan-susceptible. The DST at the NRL in Minsk was externally quality assured by the WHO/IUATLD SRL in Stockholm. The molecular characterization of the isolates was carried out in Stockholm by spoligotyping according the protocol described by Kamerbeek et al using a commercial kit (Isogen Bioscience). The octal codes were analyzed using SITVIT2 database.
Results: For both the MDR- and the susceptible group, most isolates were shown to belong to the Beijing family, seen in 33/81 (41%) and 26/82 (32%) respectively. In second place, in both groups, came the T1 family, identified in 30/81 (37%) and 16/82 (20%) of the cases. A statistical significant association to MDR-TB was demonstrated for the T1 type with the Fisher's exact test (p-value 0.0151) but not for the Beijing family (p-value 0.2564).
Conclusions: The result of this study demonstrated differences in the population structure of strains isolated from patients with MDR- and pan-susceptible TB, respectively. The major cause of MDR-TB is an ongoing transmission of resistant M tuberculosis strains, rather than to an independent development of MDR-TB.
- © 2011 ERS