AUTHOR=Bajaj Amol O. , Slechta E. Susan , Barker Adam P. 

TITLE=Rapid and Accurate Differentiation of Mycobacteroides abscessus Complex Species by Liquid Chromatography-Ultra-High-Resolution Orbitrap™ Mass Spectrometry

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=Volume 12 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.809348

DOI=10.3389/fcimb.2022.809348

ISSN=2235-2988

ABSTRACT=A liquid chromatography tandem mass spectrometry (LC-MS/MS) method based on protein profiling for the identification of clinically relevant Mycobacteroides abscessus (Mabs) complex was developed and evaluated in 32 clinical isolates. The assay accuracy was confirmed against type strains. In the present study, an innovative liquid Chromatography-Mass Spectrometry (LC-MS) method for the identification of clinically relevant microbes is tested using a model set of microbial strains. The methodology is based on protein profiling derived from Mycobacteroides abscessus complex isolates, which are used as markers of differentiation. To test its resolving power, speed, and accuracy, four ATCC type strains and 32 recent clinical isolates of closely related species collected at ARUP laboratories (10 clinical isolate strains of M. abscessus subsp. abscessus, 10 M. abscessus subsp. massiliense, 2 M. abscessus subsp. bolletii and 10 M. chelonae) were subjected to this new approach. Using different deconvolution algorithms, we identified hundreds of individual proteins, with a subpopulation of these used as species-specific markers. This assay identified 216, 260, 240 and 201 proteoforms for M. abscessus (ATCC 19977), M. massiliense (DSM 45103), M. bolletii (DSM 45149) and M. chelonae (ATCC 35752) respectively. All species were identified correctly down to the species level with 100% accuracy.  The ability to differentiate Mycobacteroides at sub-species level can in-turn be helpful for patient management. Data analysis showed ~7-17 proteoforms potentially able to differentiate between subspecies. Here, we present the first proof-of-principle study employing a fast mass spectrometry-based method to identify the clinically most prevalent species within the Mabs species complex.