Afb Mtb - Pas Automated Instrument Systems Infected Tissue

The MGIT Automated system was used for primary isolation and standard susceptibility testing of first-line drugs (10) as recommended by the manufacturer. MGIT tubes supplemented with 0.8 ml of supplement (MGIT 960 SIRE supplement; Becton Dickinson) were inoculated with 0.1 ml of the drug solution and 0.5 ml of the test strain suspension. For preparation of the drug-free growth control tube, the organism suspension was diluted 1:100 with sterile saline, and then 0.5 ml was inoculated into the tube (proportion testing). For quantitative DST using the MGIT 960 instrumentation, we requested Becton Dickinson to develop custom-designed software with the following characteristics: automated recording of the readings, additional incubation time beyond the time to positivity of the drug-free control, minimization of the number of drug-free control tubes required, graphical representation of the growth unit (GU) value increase and storage of data, and easy handling and documentation. The software is EpiCenter, version 5.53, equipped with the TB eXiST module and available from Becton Dickinson. Table 1 lists the drug concentrations used for comparative analysis. The susceptibility testing sets were placed in the MGIT 960 instrument and continuously monitored using EpiCenter (version 5.53) TB eXiST software.