Evaluation of Diagnostic Performance of Three Real-Time Polymerase Chain Reaction Assays for the Detection of Mycobacteria Species

Abstract

Background: The disease burden caused by the Mycobacterium tuberculosis (Mtb) complex (MTC) continues to decrease in most countries. However, the diseases caused by nontuberculous mycobacteria (NTM) become a public health problem. This study aimed to compare the diagnostic accuracy of three real-time PCR assays: AdvanSureTM TB/NTM real-time PCR kit (AdvanSure; LG Chem., Korea), Genedia® MTB/NTM detection kit (Genedia; Green Cross MS, Korea), and PowerChekTM MTB/NTM real-time PCR kit (Power Chek; Kogenebiotech, Korea) for the detection of MTC and NTM. Methods: A total of 102 acid-fast bacilli (AFB) smear-positive and 177 smear-negative specimens from Korea University Medical Center, Guro Hospital, were enrolled. The AFB smear-positive and negative specimens were collected from November 2016 to October 2017 and November to  December 2018, respectively. DNA extraction was performed using Genedia Mycobacteria DNA Prep Kit (Green Cross MS, Korea). The statistical analysis was performed using MedCalc18.11.6 (MedCalc Software, Belgium). Results: Among 261 specimens, 64 showed MTC growth and 28 exhibited NTM growth. The sensitivity, specificity, positive predictive value, and negative predictive value of AdvanSure/Genedia/PowerChek kits for Mtb were 96.9%/95.3%/96.9%,98.5%/99.5%/98.5%, 58.9%/80.9%/58.9%, and 99.9%/99.9%/99.9%, respectively; whereas those for NTM detection were 81.5%/44.4%/88.9%,99.6%/100.0%/98.7%, 57.3%/100.0%/32.8%, and 99.9%/99.6%/99.9%, respectively. The area under the receiver operating characteristic curve of AdvanSure and PowerChek for NTM detection was statistically different from that of Genedia (P < 0.0001). Conclusion: Three real-time PCR assays were reliable for Mtb detection in AFB-positive and-negative specimens. There was a difference between these three reagents for the accuracy of NTM detection.