European Society of Mycobacteriology - Instituto Nacional de Saúde ...

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ASSOCIATION BETWEEN BEIJING GENOTYPE AND DRUG
RESISTANCE AMONG Mycobacterium tuberculosis
ISOLATES CIRCULATING IN THE REPUBLIC OF GEORGIA
Stefan Niemann 1 , G. Khechinashvili 2 , M. Gegia 2 , N. Mdivani 2 , and Y. W. Tang 3
Molecular Mycobacteriology, National Reference Center for Mycobacteria, Research Center Borstel, Borstel, Germany
Georgian Foundation against Tuberculosis and Lung Diseases, Tbilisi, Georgia
Vanderbilt University Medical Center, Nashville, TN, USA
Rising tuberculosis (TB) rates and high levels of multidrug-resistant TB (MDR-TB) have become a major public health
problem in several parts of the former Soviet Union. High rates and transmission of MDR-TB have been noticed to be associated
with the presence of Mycobacterium tuberculosis Beijing genotype strains pointing to the importance of pathogen
genetic factors for the modulation of infection outcome and epidemiology. Here we present the first data on the population
structure of M. tuberculosis strains from the Republic of Georgia, a high incidence setting at the Black Sea Coast.
All strains were analysed by spoligotyping and 24-loci MIRU-VNTR genotyping. Identification of major M. tuberculosis
genotypes was carried out by using the MIRU-VNTRPlus database (www.miru-vntrplus.org) and a similarity analysis
performed to identify strains with identical genotyping profiles (clusters), which are indicative for the rate of recent
transmission. Anti-tuberculosis drug resistance was determined by in vitro antimicrobial susceptibility testing.
Genotyping profiles were successfully generated for 187 M. tuberculosis isolates which were further investigated. The most
prominent genotype found, was Beijing (29%), followed by LAM (18%), Ural (12%), and Haarlem (n=10) strains. Approx
50% of the isolates were grouped in clusters. When the distribution of drug resistance is considered, it was noticed that
MDR-TB was nearly completely restricted to Beijing strains. Further detailed analyses are currently in progress.
Our data underline the importance of Beijing genotype strains for the TB epidemiology in former Soviet Union countries.
However, Ural, Haarlem genotype and a large variety of strains of so far undefined lineages represent nearly two third of
the strains found in Georgia. Although Beijing strains are not as dominant as in others Eastern European countries such
as Kazakhstan, we confirm a clear association between MDR-TB and the Beijing genotype in Republic of Georgia.
European Society of Mycobacteriology | 30 th Annual Congress | July 2009 | Porto - Portugal
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