Performance Comparison Between Fourier-Transform Infrared Spectroscopy–based IR Biotyper and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry for Strain Diversity

Abstract

Background: Development of an accessible method to routinely evaluate the clonality of strains is needed in microbiology laboratories. We compared the discriminatory power of the Fourier-transform infrared (FTIR) spectroscopy-based IR Biotyper (Bruker Daltonics GmbH, Bremen, Germany) to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), using whole-genome sequencing (WGS) as the reference method.Methods: Eighty-three extended-spectrum β-lactamase-producing Escherichia coli isolates were tested using WGS, MALDI-TOF MS, and IR Biotyper. Simpson's diversity index (SDI), a statistical analysis for testing the homogeneity of a dendrogram, and the adjusted Rand index (aRI) were used to compare the discriminatory ability between typing tests. Results:The SDI (95% confidence interval) was 0.969 (0.952-0.985) for WGS, 0.865 (0.807-0.924) for MALDI-TOF MS, and 0.974 (0.965-0.983) for IR Biotyper. Compared with WGS, IR Biotyper showed compatible diversity, whereas MALDI-TOF MS did not. The concordance and aRI improved from 66.3% to 84.3% and from 0.173 to 0.538, respectively, for IR Biotyper versus MALDI-TOF MS with WGS as the reference method. IR Biotyper showed substantially improved performance in strain typing compared with MALDI-TOF MS.Conclusions: IR Biotyper is useful for diversity analysis with improved discriminatory power over MALDI-TOF MS in comparison with WGS as a reference method. IR Biotyper is an accessible method to evaluate the clonality of strains and could be applied in epidemiological analysis during an outbreak of a health care facility, as well as for research on the transmission of resistant bacteria in community settings.

A Comprehensive Methodology for Microbial Strain Typing Using Fourier-Transform Infrared Spectroscopy

“…By employing strain typing techniques like FTIR spectroscopy, researchers and public health officials can quickly identify the causative strain, trace its source, and implement preventive measures to contain the outbreak. The IR Biotyper ® has demonstrated comparability to WGS in differentiating extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolates [ 20 , 21 , 37 , 40 , 41 ]. In a prospective vancomycin-resistant Enterococcus faecium outbreak investigation, FTIR spectroscopy showed better concordance with WGS-average nucleotide identity (ANI) than MLST [ 42 ].…”

Application of Fourier Transform Infrared Spectroscopy to Discriminate Two Closely Related Bacterial Species: Bacillus anthracis and Bacillus cereus Sensu Stricto

“…Notably, the IR Biotyper ® (IRBT) system (Bruker Daltonics, Bremen, Germany) based on FTIRS technology was launched in 2017 as a promising system in the field of microbial strain typing. Multiple successful applications have been reported [13] in the field of food, veterinary and water microbiology [14][15][16], as well as in hospital hygiene [17][18][19][20][21] and probiotic production [22,23].…”

The Fourier-transform infrared spectroscopy-based method as a new typing tool for Candida parapsilosis clinical isolates

“…The carbohydrates’ IR region (1,300–800 cm −1 ) covers most of the spectral differences between isolates of the same microbial species. While FTIR (i.e., FTIR-based IR Biotyper; Bruker Daltonics, Bremen, Germany) is currently adopted for bacterial typing ( 24 ), the application of IR Biotyper on Candida species is currently limited ( 25 , 26 ). Therefore, we aimed to evaluate IR Biotyper as a new typing method for C. parapsilosis clinical isolates and compare results with those obtained with the STR method.…”