Automated High-Throughput Identification and Characterization of Clinically Important Bacteria and Fungi using Rapid Evaporative Ionization Mass Spectrometry

Abstract

27Rapid Evaporative Ionisation Mass Spectrometry (REIMS) has been shown to quickly and accurately 28 speciate microorganisms based upon their species-specific lipid profile. Previous work by members of 29 this group showed that the use of a handheld bipolar probe allowed REIMS to analyse microbial 30 cultures directly from culture plates, without any prior preparation. However, this method of analysis 31 would likely be unsuitable for a high-throughput clinical microbiology laboratory. Here, we report on 32 the creation of a customised platform which enables automated, high-throughput REIMS analysis, 33 which requires minimal user input and operation; and suitable for use in clinical microbiology 34 laboratories. The ability of this high-throughput platform to speciate clinically important 35 microorganisms was tested through the analysis of 375 different clinical isolates, collected from 36 distinct patient samples, from 25 microbial species. After optimisation of our data analysis approach, 37we achieved substantially similar results between the two REIMS approaches. For handheld bipolar 38 probe REIMS a speciation accuracy of 96.3% was achieved, whilst for high-throughput REIMS, an 39 accuracy of 93.9% was achieved. Thus, high-throughput REIMS offers an alternative mass 40 spectrometry based method for the rapid and accurate identification of clinically important 41 microorganisms in clinical laboratories without any pre-analysis preparative steps.

Rapid Evaporative Ionisation Mass Spectrometry (REIMS) Provides Accurate Direct from Culture Species Identification within the Genus Candida

“…Species specific mass spectral fingerprints are generated by applying a radiofrequency electrical current directly to the microbial colony using a stainless steel monopolar probe. The resulting vapour, containing gas phase ions of metabolites and structural lipids, is channelled to mass spectrometer using the instrument’s vacuum system; allowing for mass spectral data to be generated within one second of sample heating12.…”

Improved betulinic acid biosynthesis using synthetic yeast chromosome recombination and semi-automated rapid LC-MS screening

“…Unlike other rapid MS techniques such as Rapid-Fire 33 (Agilent), the method presented here requires no additional equipment or infrastructure. Furthermore, unlike the method presented here, other MS techniques such as REIMS 34 or MALDI-TOF-MS 23,35 lack any chromatographic separation and so may struggle to resolve some metabolites. We anticipate that the ultra-fast LC-MS method used in this study could replace many standard LC-MS workflows seeking to quantify a broad range of metabolites.…”

Exploration of Rapid Evaporative-Ionization Mass Spectrometry as a Shotgun Approach for the Comprehensive Characterization of Kigelia Africana (Lam) Benth. Fruit

“…To the best of our knowledge, this is the first work dealing with the untargeted characterization of a botanical species by the novel REIMS technology, taking also into account that the majority of the applications reported in the literature focus on animals [17,[20][21][22][23][24][25][26] and microorganisms [27][28][29][30], apart from several studies involving human cancer [14,15,18,20,31,32].…”