Evaluation of the mycobacteria MBT kit for identification of nontuberculous mycobacteria by MALDI-TOF Biotyper (Bruker).

Identification of mycobacteria is crucial for clinical management of patients. The new MBT Mycobacteria kit from the Easy MycoEx protocol (Bruker) is used for the identification of mycobacteria by MALDI Biotyper. The Easy MycoEx protocol was compared to the MycoEx protocol (1) for identification of various mycobacterial isolates collected from samples in 2021, (2) for prospective identification on primary culture during 2 periods. For 44 isolates in MGIT broth, identification rates were high and similar for both protocols (98% vs 95% at cut-off 1.6 and 91% vs 82% at cut-off 1.8). For 42 mycobacteria on Coletsos agar, identification rates were 88% versus 90% at cut-off 1.6 and 76% for both protocols at cut-off 1.8. For slow-growing mycobacteria in MGIT, reproducibility of deposit results was superior with Easy MycoEx. No difference of score was observed between 2 protocols performed on primary culture. Clinical laboratories can easily implement the Easy MycoEx protocol.

Rapid identification of fungi from respiratory samples by Bruker Biotyper matrix-assisted laser desorption/ionisation time-of-flight using ID-FUNGI plates.

Identification of moulds is crucial for the clinical management of patients. The goal of this study was to evaluate the new ID-FUNGI plate (IDFP) for the identification of moulds by MALDI Biotyper. IDFP was compared with Sabouraud with gentamicin and chloramphenicol plate (SAB) for the identification of 80 moulds from respiratory samples and eight reference strains. With the direct transfer method, species identification rose from 6% with SAB to 68% with IDFP using score cut-off 2 and from 20 to 75% using cut-off 1.7 (p < 0.001). Our study highlights that the new IDFP improves mycological diagnostic and workflow in laboratories.

Improved performances of the second generation of the ID NOW influenza A&B 2® and comparison with the GeneXpert®.

Due to the congestion of emergency wards, a rapid and accurate method for flu diagnosis is required. However, the first evaluations of the ID NOW® influenza A&B performances were heterogeneous. We aimed to (i) assess the performance of the second generation of the ID NOW® influenza A&B 2 and (ii) compare the ID NOW® to the GeneXpert® use when performed within a central laboratory. (i) Analytical performances of ID NOW® were assessed using a collection of 112 clinical samples in comparison with a reference multiplex PCR (Seegene®); (ii) Invalid rate per operator and time to result were calculated for the GeneXpert® Xpress Flu/RSV and the ID NOW® influenza A&B 2® during 2017-2018 and 2018-2019 flu outbreaks respectively. ID NOW® reaches an overall sensitivity and specificity of 96.6% and 96.1% respectively. Most of the false-negative display a CT > 37. For both instruments, a single operator was involved in about a half of all invalid results. Excluding this operator involved in most invalid result, the invalid rate was about 1% for both instruments. Time to result from sampling was significantly shorter in the ID NOW® versus the GeneXpert® group (33 vs 97 min, P < 0.01). The second generation of the ID NOW® influenza A&B 2 displays high performances, comparable with conventional PCR method. In order to prevent invalid results, we highlight the need for adequate training of operators. Also, when implemented in a central laboratory, the location of the instrument could have a strong impact on the time-to-results.