COMPARISON OF XPERT MBT/RIF CARTRIDGE TECHNOLOGY WITH MICROBIOLOGICAL METHODS FOR MBT DETECTION AND DRUG SUSCEPTIBILITY TESTING

Abstract

104 sputum samples obtained from the patients with pulmonary tuberculosis in the Central Research Institute for Tuberculosis of the Russian Academy of Medical Sciences were studied in order to compare the results of MBT detection and identification of drug susceptibility to rifampicin using test system Xpert MBT/RIF and classical microbiological methods. In addition, the aim of the research was to study the effect of concentrating of diagnostic specimens to an increase of the test Xpert MBT/RIF sensitivity. The Xpert MBT/RIF demonstrated most sensitivity with positive results in 78,2% of cases to compare with the native light microscopy of sputum, detecting 48,5% of cases, fluorescent microscopy of sputum sediment – 67,3%, cultural method with Lowenstein-Jensen medium – 56,4% and on BACTEC MGIT 960 – 71,3%.Concentration of sputum samples had no significant effect on the increase of the test sensitivity. Samples with identified non-tuberculous mycobacteria by the test Xpert MTB/RIF were recorded as negative ones, showing high specificity of the method. Complete coincidence of the results of rifampicin resistance detection using biological microchips and the system Xpert MBT/RIF was found.