Using a new molecular genetic of genotype and liquid culture medium for rapid diagnosis tb

Abstract

This paper presents the results of molecular genetic test system GenoType multyresistentens MTBDRplus. It was established that the presence of mutations associated with resistance to isoniazid, only 93.1 % of cases of MBT to isoniazid during the test in a liquid medium. Work carried out under the National Programme to combat tuberculosis Materials and methods. We investigated the clinical sputum samples from patients with pulmonary tuberculosis. The applied system GenoType. Principle DNA strip technology GenoType is that the DNA-coated strip specific test that are complementary to the derived PCR amplicon. After the single-stranded amplicon denaturation associated with tests on strip (hybridize), and visualized in a sequential enzymatic reaction with streptavydynom and alkaline phosphatase. Evaluation of hybridization is performed automatically. For culturing sputum liquid culture medium used - Middlebrook broth 7N9 VASTES MGIT system. Results and discussion . The results of molecular genetic studies of samples of sputum-concentrated and concentrated by a system GenoType not differed (P>0.05). Diagnostic value of two methods (molecular and genetic – system GenoType and phenotype – VASTES MGIT 960 system) was very high (100%). Two systems have tested positive in the study 756 (95.5 %) Mycobacterium strains that were identified in the system VASTES MGIT 960, formed Cord Factor and the results were positive identification test ID MTB MGIT they attributed to Mycobacterium tuberculosis complex. 36 (4.5 %) samples from positive MGIT tubes were negative. As a result of molecular-genetic identification of nontuberculous mycobacteria complex it was found that 18 (2.3 %) strains of mycobacteria belonging to the M. avium-intracellulare, 12 (1.5 %) mycobacterial cultures were attributed to M. kansasii, 6 (0, 7 %) cultures were identified as M. fortuitum. The results of the molecular study of MS on Mycobacterium resistance profile INN + RIF coincided in 95.5 % (894 strains) the results of testing by phenotypic proportions. In the presence of mutations associated with resistance to INH, only 93.1 % of cases observed MC M. tuberculosis to INH during TMCH in a liquid medium Middlebrook 7N9. In the presence of mutations in the genes responsible for resistance to the presence of Q, in a liquid medium only 288 (90.6 %) strains of M. tuberculosis have MS to Ofx. The strains of mycobacteria DNA were detected mutations in genes associated with MS to aminoglycosides / cyclic peptides in 299 (94.0%) cases were resistant to Am and 302 (94.9 %) cases were resistant to the results Cm DST system VASTES MGIT 960. In determining the resistance to E major differences were found between the productivity of molecular genetic and phenotypic research methods – only 206 (64, 2 %) strains of M. tuberculosis were resistant to the analysis system VASTES MGIT 960. Conclusions. GenoType system allows you to quickly carry out the identification and differentiation of Mycobacterium strains of nontuberculous mycobacteria. The results of the molecular genetic studies multyrezystents system GenoType MTBDRplus match in 95,5 % of the phenotypic test results by proportions. Using DNA strip technology GenoType to determine mutations in the genes of Mycobacterium responsible for the IPU to TDC, necessarily requires a parallel DST setting in a liquid medium