Evaluation of the Results of GenoTypeMTBDRplus v.2 Implementation for the Early Diagnosis of Multi-Resistant Forms of Tuberculosis in Zaporizhzhia Region

The article is a fragment of the research work of the Department of Phthisiology and Pulmonology of the Zaporizhzhia State Medical University under the grant "Evaluation of the results of GenoTypeMTBDRplus v.2 implementation for the early diagnosis of multi-resistant forms of tuberculosis in Zaporizhzhia region, Ukraine" (2016-2017). Logistics: Merrier Foundation (France) on the basis of a memorandum between Zaporizhzhia State Medical University and Merrier Foundation (France), 2015. Multidrug resistant tuberculosis (MDRTB) is the most common infectious disease and the most unfavorable form of tuberculosis. The GenotypeMTBRplus v.2 provides rapid identification of the M. tuberculosis complex and the detection of gene mutations in rpoB (Rif) codon and mutations in the katG and inhA codons that are associated with isoniazid resistance. Study objective is to evaluate the obtained results of the study of clinical specimens of sputum using GenoTypeMTBDRplus v.2 test system for the early diagnosis of MRTB in Zaporizhzhia region. Study object and methods. 200 patients with new and repeated cases of tuberculosis with the presence of bacterial excretion provided one sputum sample each which was used for microscopy, Genexpert MTB/RIF and GenoTypeMTBDRplus v.2 tests, cultures on the Levenstein-Jensen medium with MBT cultures. The decontamination of clinical specimens was carried out in the microbiological laboratory of the III level of Municipal Establishment "Zaporizhzhia Regional Tuberculosis Clinical Dispensary" using Eppendorf ThermoStat C (Germany). Study was carried out using the GenoTypeMTBDRplus test system v.2 (Hain Lifescience GmbH, Germany) in the department of molecular genetic research of the Department of Microbiology, Virology and Immunology of the Zaporizhzhia State Medical University in accordance with the stepwise manufacturer's instructions. Study results. The diagnosis of resistance to Rif in the GenoTypeMTBDRplus, v.2 test was higher by 18% than in the Genexpert MTB/RIF test (46,5 % versus 28,5 %, p˂0,001). When using the GenoTypeMTBDRplus, v.2 test system in Zaporizhzhia region, a significantly higher mutation rate in the rpoB gene (46,5 %) and simultaneous mutations in the 2 genes of katG + inhA (34 %) are determined. In this case, simultaneous mutations in 3 genes of rpoB + katG + inhA are diagnosed in 26,5 % of cases. Irrespective of the concentration of acid-resistant bacteria in the smear, the multidrug resistance (37,5 %) is significantly more likely to be diagnosed compared with isolated resistance to isoniazid (28,7 %) or rifampicin (2,2 %) and sensitivity of the samples (31,6 %). The sensitivity of the GenoTypeMTBDRplus test system, v.2 is 97,2 %, and the specificity is 85 %. Conclusions. Thus, performance of GenoTypeMTBDRplus, v.2 tests is more complicated than Genexpert MTB/RIF, and the tests are more sensitive. In patients with new and repeated cases of tuberculosis with the presence of bacteria, the use of GenoTypeMTBDRplus, v.2 test system provides 2 days to diagnose MDRTB in 37,5 % of cases and to start the optimal treatment of antimycobacterial therapy in a timely manner for these patients.