Application of MALDI-TOF MS to rapid identification of anaerobic bacteria

Abstract

BackgroundMatrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been rapidly developed and widely used as an analytical technique in clinical laboratories with high accuracy in microorganism identification.ObjectiveTo validate the efficacy of MALDI-TOF MS in identification of clinical pathogenic anaerobes.MethodsTwenty-eight studies covering 6685 strains of anaerobic bacteria were included in this meta-analysis. Fixed-effects models based on the P-value and the I-squared were used for meta-analysis to consider the possibility of heterogeneity between studies. Statistical analyses were performed by using STATA 12.0.ResultsThe identification accuracy of MALDI-TOF MS was 84% for species (I2 = 98.0%, P < 0.1), and 92% for genus (I2 = 96.6%, P < 0.1). Thereinto, the identification accuracy of Bacteroides was the highest at 96% with a 95% CI of 95–97%, followed by Lactobacillus spp., Parabacteroides spp., Clostridium spp., Propionibacterium spp., Prevotella spp., Veillonella spp. and Peptostreptococcus spp., and their correct identification rates were all above 90%, while the accuracy of rare anaerobic bacteria was relatively low. Meanwhile, the overall capabilities of two MALDI-TOF MS systems were different. The identification accuracy rate was 90% for VITEK MS vs. 86% for MALDI biotyper system.ConclusionsOur research showed that MALDI-TOF-MS was satisfactory in genus identification of clinical pathogenic anaerobic bacteria. However, this method still suffers from different drawbacks in precise identification of rare anaerobe and species levels of common anaerobic bacteria.

Putative Protein Biomarkers of Escherichia coli Antibiotic Multiresistance Identified by MALDI Mass Spectrometry

“…The peak at 4448.00 m/z was related to clinical strains of S. aureus [30]. The overall correct identification rate of MALDI-TOF MS for anaerobic bacteria ranged from 60% to 100% at the genus level, and from 51% to 100% at the species level [31]. Thus, this technique is demonstrated to have good functionality in the detection of bacterial species and genera in a rapid way.…”

Identification of pathogens from native urine samples by MALDI-TOF/TOF tandem mass spectrometry

“…Today, MS-based analysers are in routine use, such as the Bruker BioTyper (Bruker Daltonics) and VITEK MS Plus (bioMérieux), both detecting MS1 spectra fingerprint of most abundant proteins present in a wide array of microorganisms [24,25,26]. The US Food and Drug Administration (FDA) has issued regulatory approval for using mass spectrometry-based platform MALDI-TOF MS for routine identification of pathogenic microbes from human specimens in clinical microbiology laboratories [27,23].…”

Discrimination of bacteria using whole organism fingerprinting: the utility of modern physicochemical techniques for bacterial typing

“…Other limitations include the difficulty of coupling MALDI-MS to separation techniques, such as liquid chromatography, and limitations of the dynamic range that arise due to saturation of the detector. Together, these factors most likely compromise the use and reliability of making quantitative determinations using MALDI-MS, with the majority of studies focusing on analytes of low molecular mass, for example food products, 146 while other investigations utilised MALDI-MS as a relatively quantitative tool in biological applications, such as the analysis of proteins 147 , neuropeptides 148 , antibiotics 149 , and metabolites in biological tissues or fluids 150 .…”