Genetic diversity of Mycobacterium tuberculosis isolates at the Military Medical Academy in Ankara, Turkey

How Molecular Epidemiology Can Affect Tuberculosis Control in the Middle East Countries: A Systematic Review and Meta-Analysis

BACKGROUND

Nowadays, due to the incidence of specific strains of Mycobacterium tuberculosis and also an increase in the rate of drug resistant-TB, the mortality rate has been increased by this disease. The identification of common strains in the region, as well as the sources of transmission, is essential to control the disease, which is possible by using molecular epidemiology.

OBJECTIVES

In this survey, the studies utilizing the spoligotyping method in Muslim Middle East countries are reviewed to determine their role in the control of TB.

METHODS

All studies conducted from 2005 to June 2016 were considered systematically in three electronic databases out of which 23 studies were finally selected.

RESULTS

The average rate of clustering was 84% and the rate of recent transmission varied from 21.7% to 92.4%. The incidence of Beijing strains has been found to be rising in the abovementioned countries. In Iran and Saudi Arabia known as immigration and labour-hosting countries, respectively, rapid transmittable and drug-resistant Beijing strains were higher than those in other Muslim Middle East countries.

CONCLUSION

Considering the incidence of highly virulent strains, due to the increase in immigration and people infected with HIV, tuberculosis, especially drug-resistant form, careful monitoring is needed.

Spoligotyping and drug resistance patterns of Mycobacterium tuberculosis isolates from five provinces of Iran

Tuberculosis (TB) persists as a public health problem in Iran. Characterization of Mycobacterium tuberculosis isolates circulating in this area will contribute to understand and control the spread of the strains. The aims of this study were to understand the genetic diversity and drug susceptibility of M. tuberculosis isolates circulating in Iran and to analyze the relationship between genotype and drug resistance. A total of 291 M. tuberculosis isolates collected from TB patients were genotyped by spoligotyping. Drug susceptibility testing was performed using proportion method. Spoligotyping resulted in 75 distinct patterns. 86.2% of isolates were grouped in 35 clusters while the remaining isolates were unique. Ural was found to be the most predominant lineage (34.3%) followed by Central Asian strain (CAS) (24%), T (18.2%), Manu2 (7.5%) and Latin American-Mediterranean (LAM) (6.1%). The five largest clusters were Ural/Spoligotype International Type (SIT)127 (15.8%), CAS1/SIT26 (9.2%), T1/SIT53 (6.1%), T1/SIT284 (5.4%), and CAS1/SIT25 (4.4%). About 5% of isolates had multidrug resistance (MDR) and 10% had other resistance. MDR was significantly associated with Beijing strains, but not with Ural family. This study highlights dominance of Ural, CAS, and T families in Iran. Biogeographic specificity of CAS and T families to border provinces of Iran including Sistan-Baluchestan and Kermanshah, respectively, suggested that this family strains might be transmitted from these regions to other provinces of the country.

Molecular diversity of drug resistant mycobacterium tuberculosis strains in Western Turkey

OBJECTIVE

The aim of this study was to investigate the molecular diversity and clonal relationship of drug resistant Mycobacterium tuberculosis strains isolated in Western Turkey.

MATERIALS AND METHODS

A total of 87 strains isolated between 2006 and 2009, eight of which were rifampicin monoresistant and 79 were multidrug resistant, were analyzed with IS6110 RFLP and spoligotyping methods.

RESULTS

The results of spoligotyping showed that 7% of the strains were orphans, and 8% were undefined for family in the SpolDB4 database. Major families of the strains were LAM (38%), T (35%), Haarlem (7%), Beijing (2%), S (2%) and U (1%) families. The clustering rate by spoligotyping was calculated as 75%. The most predominant SIT cluster was SIT41 (29%). According to the results of IS6110 RFLP, 71 different patterns of IS6110 were observed. Low copy number was found in 26% of the strains. When the results of two methods were combined, the final clustering rate was calculated as 26%.

CONCLUSIONS

The genotypical distribution of drug resistant tuberculosis isolates in our region indicates genetic diversity and the clustering rate was found low in our region. However, more comprehensive and long-term molecular epidemiological studies are needed to control the drug resistant strains.

Distribution of spoligotyping defined genotypic lineages among drug-resistant Mycobacterium tuberculosis complex clinical isolates in Ankara, Turkey

Background

Investigation of genetic heterogeneity and spoligotype-defined lineages of drug-resistant Mycobacterium tuberculosis clinical isolates collected during a three-year period in two university hospitals and National Tuberculosis Reference and Research Laboratory in Ankara, Turkey.

Methods and Findings

A total of 95 drug-resistant M. tuberculosis isolates collected from three different centers were included in this study. Susceptibility testing of the isolates to four major antituberculous drugs was performed using proportion method on Löwenstein–Jensen medium and BACTEC 460-TB system. All clinical isolates were typed by using spoligotyping and IS6110-restriction fragment length polymorphism (RFLP) methods. Seventy-three of the 95 (76.8%) drug resistant M. tuberculosis isolates were isoniazid-resistant, 45 (47.4%) were rifampicin-resistant, 32 (33.7%) were streptomycin-resistant and 31 (32.6%) were ethambutol-resistant. The proportion of multidrug-resistant isolates (MDR) was 42.1%. By using spoligotyping, 35 distinct patterns were observed; 75 clinical isolates were grouped in 15 clusters (clustering rate of 79%) and 20 isolates displayed unique patterns. Five of these 20 unique patterns corresponded to orphan patterns in the SITVIT2 database, while 4 shared types containing 8 isolates were newly created. The most prevalent M. tuberculosis lineages were: Haarlem (23/95, 24.2%), ill-defined T superfamily (22/95, 23.2%), the Turkey family (19/95, 20%; previously designated as LAM7-TUR), Beijing (6/95, 6.3%), and Latin-America & Mediterranean (LAM, 5/95 or 5.3%), followed by Manu (3/95, 3.2%) and S (1/95, 1%) lineages. Four of the six Beijing family isolates (66.7%) were MDR. A combination of IS6110-RFLP and spoligotyping reduced the clustering rate from 79% to 11.5% among the drug resistant isolates.

Conclusions

The results obtained showed that ill-defined T, Haarlem, the Turkey family (previously designated as LAM7-TUR family with high phylogeographical specifity for Turkey), Beijing and LAM were predominant lineages observed in almost 80% of the drug-Resistant M. tuberculosis complex clinical isolates in Ankara, Turkey.