Background: The AdvanSure TB/NTM plus real-time PCR (AdvanSure plus PCR; LG Chem., Korea) assay has been developed to increase the diagnostic sensitivity of nontuberculous mycobacteria (NTM) compared with the currently used the AdvanSure TB/NTM real-time PCR (AdvanSure PCR; LG Chem., Korea) assay. In this study, we aimed to evaluate the performance of the AdvanSure plus PCR comparing the results with mycobacterial culture and the AdvanSure PCR.

Methods: Patients (n=199) with suspected NTM or Mycobacterium tuberculosis complex (MTC) were tested using AdvanSure plus PCR, AdvanSure PCR, acid-fast bacilli staining, and mycobacteria culture. Additionally, 200 DNA samples (n=100, MTC and n=100, NTM) were obtained from positive MTC or NTM cultures for evaluation using the AdvanSure plus PCR assay.

Results: The two real-time PCR systems showed a 94.0% (n=187/199) concordance rate (Kappa=0.94). Based on culture results, the sensitivity and specificity for the detection of MTC were 100% (45/45) and 83.8% (129/154) using AdvanSure plus PCR, and 100.0% (45/45) and 99.3% (153/154) using AdvanSure PCR, respectively. The sensitivity and specificity for NTM detection were 68.0% (n=17/25) and 90.2% (n=157/174), respectively, with AdvanSure plus PCR, and 64.0% (n=16/25) and 95.4% (n=166/174), respectively, using AdvanSure PCR. With culturepositive samples, AdvanSure plus PCR tested positive for 100% of both the MTC and NTM specimens. Seven (out of 200) culture-positive samples tested positive for both MTC and NTM using the AdvanSure plus PCR.

Conclusion: AdvanSure plus PCR had increased sensitivity but decreased specificity compared with AdvanSure PCR for the detection of NTM. The AdvanSure plus PCR assay can be used for the simultaneous detection of MTC and NTM in direct specimen and culture.