Extremely high prevalence of multidrug resistant tuberculosis in Murmansk, Russia: a population-based study.

Drug resistance and molecular epidemiology of tuberculosis (TB) in the Murmansk region was investigated in a 2-year, population-based surveillance of the civilian population. During 2003 and 2004, isolates from all culture-positive cases were collected (n = 1,226). Prevalence of multi-drug resistance (MDR) was extremely high, as 114 out of 439 new cases (26.0%), and 574 out of 787 previously treated cases (72.9%) were resistant to at least isoniazid (INH) and rifampin (RIF). Spoligotyping of the primary MDR-TB isolates revealed that most isolates grouped to the Beijing SIT1 genotype (n = 91, 79.8%). Isolates of this genotype were further analyzed by IS6110 RFLP. Sequencing of gene targets associated with INH and RIF resistance further showed that the MDR-TB strains are highly homogeneous as 78% of the MDR, SIT1 strains had the same resistance-conferring mutations. The genetic homogeneity of the MDR-TB strains indicates that they are actively transmitted in Murmansk.

[Polymerase chain reaction to determine and control drug-resistant Mycobacterium tuberculosis strains].

Real-time polymerase chain reaction was used to develop a one-stage procedure for molecular genetic analysis of Mycobacterium tuberculosis (MBT) DNA in order to determine mutations associated with drug resistance to the antituberculous agents: isoniazid and rifampicin. To analyze the spread of drug-resistance of the causative agent of tuberculosis in Russia, two thousand MBT strains were studied in 24 regions of all the federal districts. Testing 1406 MBT strains isolated by first detected and untreated patients revealed multidrug resistance (MDR) in 21.9% of cases. MRD was detected in 58.5% of the previously treated patients with MDR. The agreement of molecular genetic analysis of drug resistance with the results of cultural tests of 1096 strains was 94%.