High rates and transmission of multidrug-resistant (MDR) tuberculosis (TB) have been associated with theMycobacterium tuberculosis complex (MTBC) Beijing lineage, pointing to the importance of pathogen genetic factors for the modulation of infection outcome and epidemiology. We present here an in-depth analysis of the population structure of MTBC strains from the Republic of Georgia, a high-incidence setting at the Black Sea Coast. Phylogenetic lineages were identified based on 24-locus MIRU-VNTR (for mycobacterial interspersed repetitive unit-variable number tandem repeat) and spoligotyping analysis. Clusters of strains with identical genotyping profiles were determined as an indicator for the rate of recent transmission. Among the 183 M. tuberculosis isolates investigated, the most prominent lineage found was Beijing (26%), followed by the LAM (18%), Ural (12%), and Haarlem (5%) strains. A closely related previously undefined phylogenetic group (62 strains) showed a genotyping pattern similar to laboratory strain H37RV and was denominated as "Georgia-H37RV-like." Although isoniazid resistance was found among strains of different lineages, MDR TB was nearly completely restricted to Beijing strains (P < 0.0001). Approximately 50% of the isolates were grouped in clusters, indicating a high rate of recent transmission. Our data indicate that, in addition to the confirmation of the importance of Beijing genotype strains for the TB epidemiology in former Soviet Union countries, a high-population diversity with strains of the LAM, Ural, Haarlem, and a previously undefined lineage represents nearly two-thirds of the strains found in Georgia. Higher rates among previously treated and MDR TB patients point to a higher potential of lineage Beijing to escape therapy and develop MDR TB.Drug-resistant Mycobacterium tuberculosis complex (MTBC) strains have emerged worldwide as a serious threat for tuberculosis (TB) control. Rates of multidrug-resistant (MDR) strains (i.e., resistance at least to isoniazid [INH] and rifampin [RIF]) have reached levels of up to 14% among patients never treated and up to 40% among previously treated patients in several MDR TB "hot spots" such as such as Karakalpakstan (Uzbekistan) and Kazakhstan in Eastern Europe (10, 37). Every year an estimated 489,000 cases of MDR TB arise globally (36). MDR TB is associated with much poorer treatment outcomes than for drug-susceptible TB, with a much higher risk of developing further resistances (2, 7). Prolonged periods of infectivity result in enhanced transmission of drug-resistant strains, further accelerating the rates of drug resistance (3). Even more worrisome is the emergence of a nearly untreatable form of TB, namely, extensively drug-resistant TB (XDR TB), which is defined as MDR plus additional resistance to any fluoroquinolone and at least one of three injectable drugs (i.e., amikacin, kanamycin, or capreomycin). A recent survey confirmed the worldwide presence of XDR strains, with rates of up 15% of MDR TB cases (30).Considering the difficulti...

MDR-TB has emerged as a serious public health problem in Georgia and will greatly impact TB control strategies.

BACKGROUND: Current laboratory methods for monitoring the response to therapy for tuberculosis (TB) rely on mycobacterial culture. Their clinical usefulness is therefore limited by the slow growth rate of Mycobacterium tuberculosis. Rapid methods to reliably quantify the response to anti-TB drugs are desirable.

We developed a QIAplex system for the simultaneous detection of 24 Mycobacterium tuberculosis gene mutations responsible for resistance to isoniazid (INH), rifampin (RIF), streptomycin (STM), and ethambutol (EMB) in 196 M. tuberculosis isolates recovered in the Republic of Georgia. In comparison to phenotypic susceptibility tests, the QIAplex showed sensitivity and specificity of 85.4% and 96.1% for INH, 94.4% and 99.4% for RIF, 69.6% and 99.2% for STM, 50.0% and 98.8% for EBM, and 86.7% and 100.0% for multidrug resistance, respectively. The dominant resistance mutations revealed were a mutation in katG resulting in S315T (katG S315T), rpsL K43R, and rpoB S531L. Mutations katG S315G and S315T and rpoB S531L were detected with higher frequencies in pretreated patients than in naive patients (P < 0.05). Simultaneous detection of 24 common drug resistance-related mutations provides a molecular tool for studying and monitoring M. tuberculosis resistance mechanism and epidemiology.

Drug-resistant tuberculosis (DR-TB) is a global challenge and a major contributor of death from anti-microbial resistance. With the main aim to determine factors contributing to treatment outcomes observed among DR-TB patients in the countries in Eastern Europe and Central Asia (EECA), a multi-method study was conducted in: Azerbaijan, Belarus, Romania, Tajikistan and Ukraine. Both quantitative and qualitative methodologies were used for data collection and analysis. The quantitative approaches included a desk review of documents related to the DR-TB responses and an analysis of clinical records of DR-TB patients in selected health facilities of the five countries. Qualitative methods included in-depth interviews with national TB programme (NTP) managers, other healthcare providers and non-governmental organizations (NGOs) workers, as well as interviews and Focus Group Discussions (FGDs) with DR-TB patients. The desk review of 38 reports identified as the main challenges to address DR-TB financial and/or management issues and adverse events of the medicines. The most common recommendations related to treatment outcome focussed on general programme management, treatment regimen composition, clinical management and social support for the patients. In all the five countries the NTPs still have a vertical structure. Some integration into the primary health care system (PHC) already exists but further involvement of PHC facilities is feasible and recommended. Interviews with stakeholders indicated that alcoholism and homelessness and a lack of appropriate response to these issues remain as major challenges for a sub-set of patients. Civil society groups, NGOs and communities are substantially engaged in providing different services to DR-TB patients, especially in Ukraine, Romania and Tajikistan. Data from clinical records of 212 patients revealed that independent risk factors for unfavourable treatment outcome (death, loss to follow-up, failure) were culture-positivity at two months of treatment, history of treatment with second-line drugs and homelessness. More powerful, less toxic and shorter oral treatment regimens as well as comprehensive patient support are needed to improve treatment outcome of patients with DR-TB.