Evaluation of a new molecular assay for tuberculous and nontuberculous mycobacteria rapid detection in clinical samples
A Camaggi(1) M Mantovani(1) M S Caroppo(1) S Andreoni()
1:AOU Maggiore della Carità, Laboratory of Microbiology and Virology – Novara, Italy
The introduction of molecular diagnostic assays has contributed to better control of tuberculous (TB). Since 2013, WHO recommended rapid molecular tests as the initial TB diagnostic test. In the last years, nontuberculous mycobacteria (NTM) have emerged as important human pathogens too. In tuberculous low incidence countries, the rapid detection of NTM versus Mycobacterium tuberculosis complex (MTB) are useful for the management of mycobacterial diseases, because many NTM strains are resistant to the antibiotics used for TB treatment. In this study, we evaluated the performance of a novel real-time PCR cartridge-based kit, the STANDARD M10 MTB/NTM assay (SD Biosensor, Suwon, South Korea-M10), for the detection of MTB and NTM, in pulmonary and extrapulmonary samples in less than two hours. The results obtained with M10 were compared with the microscopy (AFB), culture and Xpert MTB/RIF Ultra (ULTRA) results. In this study, 37 several specimen types (sputum, bronchial wash samples, abscesses, cerebrospinal fluid, urine) collected in our Clinical Laboratory were investigated. M10 and ULTRA MTB results were both the same, except for one cerebrospinal fluid (trace ULTRA and M10 negative) and one urine samples (low ULTRA and negative M10 result but MTB culture negative). NTM results were positive for all microscopy positive specimens whereas only 4 of the 12 negative AFB samples but NTM positive culture samples were detected by M10. These preliminary data suggest that STANDARD M10 MTB/NTM could be included in the clinical microbiology laboratories workflow of countries with low incidence of tuberculous that daily searches for MTB and NTM.