Direct liquid extraction surface analysis mass spectrometry of cell wall lipids from mycobacteria: Salt additives for decreased spectral complexity

Conner, Alexander N.; Jarvis, Jessie R.; Alderwick, Luke J.; Griffiths, Rian L.

Abstract

Rationale

Lipids are important mycobacterium cell wall constituents; changes are linked with drug resistance. Liquid extraction surface analysis (LESA) enables direct sampling in a highly sensitive manner. Here we describe protocols for the analysis of lipids from bacterial colonies. Lipids form various adducts, complicating spectra. Salt additives were investigated to circumvent this problem.

Methods

Chloroform:methanol mixtures were studied for lipid extraction and analysis by LESA‐MS. The inclusion of (ESI‐compatible) acetate salts of sodium, potassium or lithium in the extraction solvent was investigated.
Results

We report the detection of bacterial cell wall lipids from mycobacterial species using LESA for the first time. Sampling protocols were optimised for the use of volatile extraction solvents. The inclusion of acetate salt additives in the sampling solvent significantly reduces spectral complexity in comparison with no additives being used.

Conclusions

LESA offers a sensitive technique for bacterial lipid phenotyping. The inclusion of an acetate salt in the sampling solvent drives adduct formation towards a specific adduct type and thus significantly reduces spectral complexity.

Citation

Conner, A. N., Jarvis, J. R., Alderwick, L. J., & Griffiths, R. L. (2021). Direct liquid extraction surface analysis mass spectrometry of cell wall lipids from mycobacteria: Salt additives for decreased spectral complexity. Rapid Communications in Mass Spectrometry, 35(S2), Article e8523. https://doi.org/10.1002/rcm.8523

• Journal Article Type: Article
• Acceptance Date: Jul 2, 2019
• Online Publication Date: Oct 29, 2019
• Publication Date: 2021-04
• Deposit Date: Nov 3, 2020
• Publicly Available Date: Nov 26, 2020
• Journal: Rapid Communications in Mass Spectrometry
• Print ISSN: 0951-4198
• Electronic ISSN: 1097-0231
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 35
• Issue: S2
• Article Number: e8523
• DOI: https://doi.org/10.1002/rcm.8523
• Keywords: Organic Chemistry; Analytical Chemistry; Spectroscopy
• Public URL: https://nottingham-repository.worktribe.com/output/3794542
• Publisher URL: https://onlinelibrary.wiley.com/doi/10.1002/rcm.8523
• Additional Information: Received: 2019-02-20; Accepted: 2019-07-02; Published: 2019-10-29