Analysis of Mycobacterium tuberculosis Complex Strains Isolated from the Samples of Patients Living in Northern Syria

Abstract

Tuberculosis causes serious mortality and morbidity worldwide each year. A lot of effort and money is spent for the diagnosis and treatment of tuberculosis all over the world. The importance that countries give to health policies and public health is inversely proportional to the incidence of tuberculosis and multidrug resistant tuberculosis. The aim of our study was to evaluate the resistance profiles of Mycobacterium tuberculosis complex strains which were isolated from sputum samples, collected by World Health Organisation from patients living in the northern region of Syria, where health services were disrupted due to the civil war. According to the protocol signed between the World Health Organization and our hospital; sputum samples taken from tuberculosis patients living in Afrin, Azez and Idlib regions or suspected of being resistant to anti-tuberculosis drugs were studied in our hospital. The cultivation process was performed in our laboratory using Löwenstein Jensen media and MGIT-960 system. The susceptibility tests for primary anti-tuberculosis drugs were performed using MGIT-960 system for M.tuberculosis complex isolates. The isolates identified as MDR/RD-TB (multi-drug-resistant-rifampicin-resistant tuberculosis) were sent to National Tuberculosis Reference Laboratory of Public Health Institution of Türkiye for susceptibility testing to first and second line drugs. Mutation and wild-type determination were studied by "Line Probe Assay (LPA)" method to investigate the susceptibility of the isolates to isoniazid, rifampicin, fluoroquinolone and aminoglycoside/cyclic peptide. The results obtained from the patients were collected and evaluated retrospectively from the records. Growth was observed in 18 samples out of 171 sputum samples from 67 patients; 13 isolates were detected as MDR-TB while one isolate was detected as mono RR-TB. The rate of mono RR-TB was 1.5% and the rate of MDR-TB was 19.4%. MUT3 causing rifampicin resistance was detected in 17.9% of the patients, katG/MUT1 causing isoniazid resistance in 17.9% and WT loss causing aminoglycoside/cyclic peptide resistance were detected in 19.4% of the patients. Neither fluoroquinolone resistance nor a mutation leading to fluoroquinolone resistance was detected in the study. When the sputum samples taken from the patients living in Northern Syria were examined, the frequency of MDR-TB was found to be quite high. MDR-TB, which is an important public health problem, was found at high rates due to the internal turmoil in the region and poor accessibility to health services. Since the gene mutations causing drug resistance with the LPA method differ with the conducted studies, it is important to evaluate the dominant gene mutations for determining the TB treatment strategies in the region.