Studio di un nuovo algoritmo diagnostico per l’identificazione dei micobatteri non tubercolari (NTM)

NTM (Non tuberculous mycobacteria) count more than 160 species, widely dispersed in the environment as saprophites, but they can cause severe infections in human. The identification of NTM to the species level is extremely important to determine whether it is or not a NTM infection and the proper treatment. Therefore, many techniques have been developed for the accurate and rapid identification of NTM, among which PCR-RFLPs (PRAs) are easy, rapid and inexpensive tools for identifying mycobacterial species. The aim of this work was to realise a new PCR-RFLP technique with a high discriminatory power, cost effective, easy to be performed and able to overcome the limits of those used nowadays, using a new target, called dnaK, described as a powerful potential target for the identification of NTM.30 mycobacterial species were used to develop a novel algorithm targeting locus dnaK and using restriction enzymes Fau I and BstMW I, which was successfully blind tested on 45 clinical micobacterial isolates that had been already identified to the species level with other techniques. Moreover, dnaK-PRA was tested on 40 clinical samples whose cultures were positive for mycobacteria and correctly detect and identified mycobacterial species in up to 82% of them.The results obtained showed that dnak-PRA is a reliable tool for the identification of mycobacterial isolates to the species level and can be helpful to detect and identify mycobacteria directly from clinical samples.