Comparison of a New Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry Platform, ASTA MicroIDSys, With Bruker Biotyper for Species Identification

Abstract

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, with its accuracy and speed, is widely used for bacterial identification. The ASTA MicroIDSys system (ASTA, Korea) was recently developed for species identification. We compared its performance with that of Bruker Biotyper (Bruker Daltonics, Germany). Microbes were recovered from sputum, urine, and pus samples from patients admitted to a tertiary care hospital in Korea from January to April 2016. Matrix solution (α-cyano-4-hydroxycinnamic acid) was used, and the peptide profiles acquired from the Microflex LT (Bruker Daltonics) and Tinkerbell LT (ASTA) were analyzed by using their respective software. From 5,322 isolates, Bruker Biotyper identified 163 species; fifty species from 4,919 isolates were identified more than 10 times, including Klebsiella pneumoniae (n=571), Acinetobacter baumannii (n=436), Pseudomonas aeruginosa (n=358), Escherichia coli (n=372), Staphylococcus aureus (n=511), S. epidermidis (n=444), Enterococcus faecium (n=262), E. faecalis (n=220), and Candida albicans (n=248). Identical results, confidence scores (≥ 2.0 for Bruker Biotyper), and acceptable scores (≥140 for ASTA MicroIDSys) were obtained for 86.1% of isolates. Of 4,267 isolates, 99.2% showed acceptable scores in both systems. Results from the ASTA MicroIDSys showed good agreement with those from the Bruker Biotyper. The ASTA MicroIDSys could reliably identify clinically important microorganisms.