Evaluation of the Roche Amplicor polymerase chain reaction system for detection of Mycobacterium tuberculosis complex...

Roche Diagnostic Systems Inc. have recently developed a commercial PCR (Amplicor) for direct amplification of Mycobacterium tuberculosis Complex (MtbC) from sputum and bronchial washes. Detection of MtbC specific sequence is achieved by hybridization with an oligonucleotide probe. The aim of this study was to compare the Amplicor PCR system for detection of MtbC with microscopy, culture and an in-house PCR method. The commercial assay correctly identified 35/37 microscopy positive specimens compared to 34/37 with the in-house method and 7/13 microscopy negative, culture positive samples compared to 2/13 with the in-house procedure. Negative PCR results were obtained for 32 culture negative specimens and 6 specimens which yielded mycobacteria other than MtbC, indicating a specificity of 100%. The sensitivity of the commercial assay was determined to be approximately 10 organisms compared to 100 organisms with the in-house method. The Amplicor PCR system is specific, sensitive and easy to perform. It also has the advantages of being standardized and quality controlled.