It has been recognized that management of the global TB problem can only be achieved with efficient and rapid diagnosis of the disease and the subsequent appropriate treatment of the patients. An innovative method, termed Phage Amplification Technology, uses bacteriophage to report the presence of viable mycobacterium tuberculosis (MTh) in a sample. Two products have been developed now by Biotic Laboratories Ltd, using this technology: FASTPlaque TB, which is a test for MTB detection and FASTPlaque TBRIF for rifampicin susceptibility testing. In this study the performance of these technologies is compared with the results of conventional culture on Lowenstien Jensen (Li) media and Mycobacterium Growth Indicator Tubes (MGIT). This study included; 50 tuberculous patients and 20 patients with chest disease other than tuberculosis served as control group (L11). Newly diagnosed tuberculous patients were classified into group I and II (each, 25 patients) of sputum Ziehl Neelsen (ZN) positive and ZN negative cases respectively. From group I and II, 25 patients were selected to perform rifampicin susceptibility testing served as group IV. Sputa were decontaminated, digested and concentrated by the standard NALC-NaOH treatment. From both groups I and II Li slopes in duplicate were inoculated, culture on MGIT also was done. FASTPlaque TB test was performed for all patients. FASTPlaque TB RIF
*Department of Clinical Pathology,**Department of Chest Benha Faculty of Medicine
thr rifampicin susceptibility in comparison with the results of MGIT susceptibility were done for group IV. This study confirmed that the mean time of detection of MTB by FASTPlaque TB test is 2 days for the tuberclous patients (92% & 68% in group I and II respectively) with high significant difference in relation to the detection time by Li medium (27.7± 3.8 days) in group I \and in group 11 (30.9±5.8 days). Meanwhile, the mean time of detection of MTB by MGIT was 7.5±1.9 days in 96% of group 1 and was 9.8±2.4 days in 76% of group II which is also higher than that of FASTPlaque TB test. For group III (control group), no growth could be detected by IJ medium, MGIT and FASTPlaque TB test indicating 100% specificity. For group IV, 15 cases (60%) were sensitive for rifampicin and 10 cases (40%) were resistant for rifampicin with 100% sensitivity and 100% specificity in comparison with the results of MGIT. A combination of smear microscopy and FASTPlaque detected 80% of all TB positive specimens. FASTPlaque TB results were available within 48 hours from receiving the samples, so rapidly we can confirm TB in smear positive and to provide quick and certain diagnosis in smear negative TB. FASTPlaque TB RIP' test is a rapid and reliable bacteriophage based test to detect the rifampicin susceptibility within two days also. The tests are easy to perform, require no specialized equipment |
