[Mycobacterium tuberculosis strains isolated from Van region four different sensitivity detection method antimycobacterial agents]

Abstract

Introduction: The purpose of this study is detecting the susceptibility rates of 58 Mycobacterium tuberculosis complex strains which were isolated from patient specimens sent to our mycobacteriology laboratory, for major anti-tuberculosis drugs like streptomycin, isoniazid, rifampicin and ethambutol with three different systems and agar proportion method and compare the accessibility, speed, specificity and sensitivity of these three systems.

Materials and methods: With this purpose, 58 (96.6%) strains out of 60 which were isolated from the patients attended to the mycobacteriology laboratory were identified as M. tuberculosis complex with conventional methods. These strains susceptibilities to four major anti-tuberculosis drugs were detected with Manuel MGIT AST SIRE system, BacT/ALERT 3D system MB/BacT SIRE, TK anti-TB system and compared with reference method in Middlebrook 7H10 media.

Results: As a result, INH resistance in Van province with agar proportion method was detected as 12%, followed by INH + RIF resistance of 1.7% and INH + SM resistance of 1.7%. These result compared with other studies conducted country wide are in median range. The systems included in our study were determined to have 100% sensitivity for all of the drugs for detecting resistance and sensitivity rates. Specificities for INH for TK anti-TB, MGIT and MB/BacT were detected as 98%, 96% and 95% respectively. Multidrug resistance rates were detected in 100% sensitivity and specificity with all of the three systems. Only MB/BacT system gave a false negative RIF resistance for 1 strain. Fastest system according to resistance determination times is found to be the MGIT system.

Conclusion: However, presence of INH + RIF resistance pattern, indicates inadequate treatment programs in our region. As a result these three systems are fast and reliable systems for antimicrobial susceptibility testing of Mycobacterium spp. to be used in routine mycobacteriology laboratories.