Evaluation of the Copan Myco-TB kit for the decontamination of respiratory samples for the detection of Mycobacteria

Abstract

The purpose of this study was to test a newly developed decontamination and fluidization kit for processing respiratory specimens for the detection of mycobacteria: the Myco-TB procedure (developed by Copan (Brescia, Italy)). This technique was compared with the Zephiran decontamination method in use in our hospital. Respiratory specimens (n = 387: 130 endotracheal/bronchial aspirates, 172 bronchoalveolar lavages and 55 sputa) submitted to the University Hospital of Brussels between January 2016 and March 2017 were included. All samples were divided into two aliquots: one was subjected to the Myco-TB method and one to the Zephiran technique prior to culture. The sensitivities for culture for the Zephiran technique on solid media, the Myco-TB method on solid media and Myco-TB combined with the MGIT™ system were respectively 67%, 87% and 89%. The contamination rates were 22% with both the Zephiran and Myco-TB method on solid media and only 4% with the Myco-TB kit combined with the MGIT™ system. For direct microscopy, the sensitivities of the Zephiran method and the Myco-TB method were equal (40%) when the centrifugation time was 20 min. The Myco-TB decontamination method is easy and rapid to perform. It is more sensitive for culture as compared to the Zephiran method and gives lower contamination levels when combined with the MGIT™ technique. When increasing the centrifugation step to 20 min, the sensitivity of direct microscopy is equal to the Zephiran method.