Multicenter Performance Evaluation of MALDI-TOF MS for Rapid Detection of Carbapenemase Activity in Enterobacterales: The Future of Networking Data Analysis With Online Software

Abstract

In this study, we evaluate the performance of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for rapid detection of carbapenemase activity in Enterobacterales in clinical microbiology laboratories during a multicenter networking validation study. The study was divided into three different stages: “software design,” “intercenter evaluation,” and “clinical validation.” First, a standardized procedure with an online software for data analysis was designed. Carbapenem resistance was detected by measuring imipenem hydrolysis and the results were automatically interpreted using the Clover MS data analysis software (Clover BioSoft, Spain). Second, a series of 74 genotypically characterized Enterobacterales (46 carbapenemase-producers and 28 non carbapenemase-producers) were analyzed in 8 international centers to ensure the reproducibility of the method. Finally, the methodology was evaluated independently in all centers during a 2-month period and results were compared with the reference standard for carbapenemase detection used in each center. The overall agreement rate relative to the reference method for carbapenemase resistance detection in clinical samples was 92.5%. The sensitivity was 93.9% and the specificity, 100%. Results were obtained within 60 min and accuracy ranged from 83.3 to 100% among the different centers. Further, our results demonstrate that MALDI-TOF MS is an outstanding tool for rapid detection of carbapenemase activity in Enterobacterales in clinical microbiology laboratories. The use of a simple in-house procedure with online software allows routine screening of carbapenemases in diagnostics, thereby facilitating early and appropriate antimicrobial therapy.

A Review of Carbapenem Resistance in Enterobacterales and Its Detection Techniques

“…This technique identifies specific resistant profiles (e.g., KPC and MBLs) of bacteria at the species and genus level from single isolated colonies within 1–4 h, with 72.5–100% sensitivity and 98–100% specificity; however, it has issues regarding OXA-48 identification [ 40 , 123 , 124 ]. Further, the combination of automation and the implementation of a user-friendly interface recently made MALDI-TOF MS popular in clinical laboratories [ 123 , 125 , 126 , 127 ].…”

Recent Advances in the Use of Molecular Methods for the Diagnosis of Bacterial Infections

“…Several approaches based on MALDI-TOF MS have been used for the rapid detection of antimicrobial resistance in bacteria. MALDI-TOF MS has been used to detect the presence of carbapenemases for the rapid detection of antimicrobial resistance [88,90]. The most promising applications include: (1) the determination of β-lactamase activity by visualizing the peak shift of β-lactam ring hydrolysis; (2) the detection of the specific peak for AMR determinants; (3) the detection of specific peaks for proteins co-expressed with AMR determinants; and (4) a comparison of the area under the curve of the MALDI spectra of bacteria incubated with or without antimicrobial drugs [88,90].…”

Detection accuracy and clinical applications of DP-TOF mass spectrometry

“…5 Future applications of MALDI-TOF MS in clinical diagnosis will likely be driven by technical advances in equipment, software, and sample preparation. [6][7][8][9] Moreover, new MALDI-TOF MS applications may be developed that could revolutionize molecular diagnostics, such as nucleotide detection. 10 MALDI-TOF MS techniques offer new approaches in pharmacogenomics, genetic disease testing, methylation, laboratory medicine, toxicology, microbiology, health management, and molecular pathology; they have also enabled reliable, costeffective, and rapid detection of amplified polymerase chain reaction (PCR) products.…”