Identification of Isolate Mycobacteria Strains in tuberculosis National Reference Laboratory of Mali: diagnostic value of SD BIOLINE TB Ag MPT64 Rapid

Abstract

Introduction: The distinction between Mycobacterium tuberculosis complex (MTBC) and Non tuberculous Mycobacteria (NTM) infection is essential for an appropriate treatment. Unfortunately this distinction is not done at regular basis in resource limited settings, as the decision to start is based on smear microscopy which cannot distinguish between bacterial species. SD Bioline rapid test for the detection of Ag MPT64 which is specific to Mycobacterium can be an interesting alternative for differential diagnosis. Objective: To identify MTBC strains isolated at the National Reference Laboratory (NRL) of tuberculosis, Bamako using Ag MPT64 immunochromatographic SD Bioline rapid test relative to traditional biochemical and molecular tests. Methods: We detected MPT64 proteins from both human and animal mycobacterial strains. Human strains were isolated from patients who were referred to NRL for culture and drug susceptibility testing (DST). SD Bioline rapid test results were confirmed using traditional biochemical tests, morphological and molecular techniques. Results: We found that SD Bioline rapid test has a specificity and sensitivity of respectively 100% and 99%. There was only one false negative (FN) case which was identified by traditional biochemical and morphological techniques. Conclusion: This is a simple technique, and may provide a fast, cheap and easy-to-perform alternative method to distinguish between mycobacterial strains in resource limited settings. However, negative results should be confirmed by another identification method such as morphological identification.