Vérification en portée A d'une méthode de PCR triplexe pour la détection de Chlamydia trachomatis, Neisseria gonorrhoeae et Mycoplasma genitalium

In 2017, at the Beauvais hospital laboratory, a real time PCR system has been acquired. This work describes the method verification of a real time PCR kit, Urethritis basic®, FTD, in range A, for the qualitative detection of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Mycoplasma genitalium (MG). According to the ISO 15189 standard, a risk analysis and a verification of some performance criteria are performed on site. Intermediate precision for NG is evaluated on two samples giving equivocal results. Following runs gives negative results. Comparison between the new and the previous end-point PCR method (GenoQuick®CT, Hain Lifescience) for the detection of CT is performed on 46 samples. Four samples show discordant results (all positive with the previous method and negative with the new one). Accuracy is assessed by two EQA (External Quality Assessment) for CT and NG and gave expected results. Our tests of carry-over contamination, by alternating positive and negative samples, did not identify any contamination. Finally, we implemented continuous verification by Levey-Jennings charts established using threshold cycles of controls. This work let to conclude on the ability of the method while confirming the interest of controlling equivocal NG results. In addition, it provides a tool to continuously monitor the performance.