Sensitivity of a transcription-mediated amplification method (Aptima Mycoplasma genitalium assay) to detect M. genitalium in vitro

Introduction: Mycoplasma genitalium is a known causative pathogen for some sexually transmitted infections. Nucleic acid amplification tests are a recommended method for detecting M. genitalium. A transcription-mediated amplification (TMA) nucleic acid amplification test to detect M. genitalium, the Aptima Mycoplasma genitalium assay was approved by the Food and Drug Administration in the United States and has been used in other countries. The purpose of this study is to determine the sensitivity of TMA test as the detection limit for 20 strains. Method: The sensitivity of the TMA test was re-examined using 20 strains in vitro and the detection limit was estimated by comparison with the MgPa quantitative real-time PCR (qPCR) method. The M. genitalium strains used were isolated from Denmark, Norway, Sweden, France and Japan, and included macrolide or fluoroquinolone resistance. Stock strains were used at several dilutions, with each dilution of each strain examined using both TMA test and qPCR methods. Result and conclusion: Estimated DNA loads of M. genitalium as the detection limit were 0.03-0.87 genome equivalents/mL. Sensitivity for TMA test was almost 100-fold higher than for the qPCR method. (C) 2020 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.