Comparison of the Purelyse®-IS6110 nested PCR with the Xpert® MTB/RIF test in clinical samples with suspected tuberculosis

Tuberculosis (TB) has a high incidence, prevalence and mortality in the world. Due to its high level of transmission and long-term pharmacological treatment, it is important to have sensitive and specific diagnostic tests. Recently, the PureLyse (R) system, which is a novel DNA extraction method, was proposed to be an important tool for molecular diagnosis of TB. Here, we compare the PureLyse (R) system followed by an IS6110 nested PCR (PureLyse (R) - IS6110 nested PCR) with the Xpert (R) MTB/RIF test for Mycobacterium tuberculosis complex (MTBC) identification in 40 clinical samples. Among the 40 samples, 26 samples were positive and 14 negative for the Xpert (R) MTB/RIF test as well as for the PureLyse (R) - IS6110 nested PCR. According to the Xpert (R) MTB/RIF test, positive samples presented different bacillary concentrations from "High" to "Very low" and rifampin resistance was observed in 5 samples. The concordance of both molecular methods makes the PureLyse (R) - IS6110 nested PCR suitable for MTBC detection in patients for low-income resources.