A head-to-head comparison of five MALDI-TOF mass spectrometry systems for detection of clinically relevant bacteria and fungi, a single center study

Abstract

We compared the accuracy of five MALDI-TOF MS, Bruker Biotyper, Biotyper Sirius, bioMérieux VITEK MS, VITEK MS Prime, and ASTA MicroIDSys for the identification of bacteria and fungi that are commonly isolated in clinical microbiology laboratories.Between May 1 and 31, 2023, a total of 627 isolates from the clinical microbiology laboratory at Severance Hospital were identified with Bruker Biotyper using five instruments. The isolates consisted of 221 gram-positive bacteria, 195 Enterobacteriales, 134 non-fermenting gram-negative bacteria, 17 anaerobes, 14 fastidious bacteria, 25 yeasts, and 21 other species. If the results from all five instruments agreed at the species level, no further analysis was performed. If any of the five instruments disagreed, the strain was identified by 16s rRNA sequencing. If 16s did not yield a species-level identification, whole genome sequencing was performed to identify the species, and the results were used to determine matches and discrepancies. We also compared the time required for identification across the five instruments.Biotyper, Sirius, VITEK-MS, Prime, and MicroIDSys showed 93.5%, 94.6%, 95,1%, 94.1%, and 94.7% of accuracy at the genus level, respectively, and 78.3%, 79.6%, 78.9%, 78.1%, and 78.3% at the species level. The accuracy was excellent for gram positive bacteria and anaerobe, but generally lower for entero- and fastidious bacteria. The turnaround times for the five instruments were 30.3s, 23.8s, 112.5s, 82.1s, and 53.0s per spot, respectively.The five instruments performed generally comparable in their ability to identify commonly isolated clinical strains, with differences in species-specific accuracy and turnaround time.

Keywords

• MALDI-TOF
• bacteria
• fungi
• accuracy
• clinical microbiology