Detection of tuberculostearic acid in mycobacteria and nocardiae by gas chromatography and mass spectrometry using selected ion monitoring

The mycobacterial cell envelope is composed of lipids and glycolipids ranging from conventional membrane glycerophospholipids (e.g., phosphatidylinositol, phosphatidylglycerol, phosphatidylserine, phosphatidylethanolamine, and cardiolipin) to highly complex mycolic acid and lipoarabinomannan, which are species-specific lipids (e.g., sulfolipids, phenolic glycolipids, and lipooligosaccharides). This variety and diversity represents an incredible reservoir of specific biomarkers that can be used to detect mycobacterial infections via the identification of lipids and glycolipids found in all mycobacterial species (e.g., phosphatidyl-myo-inositol-mannosides [PIMs]), and this information can be used to determine the species and subspecies of mycobacteria causing infection in order to select the appropriate drug regimen. In this chapter, we emphasize the history and current use of mycobacterial lipids in the rapid detection of Mycobacterium tuberculosis from urine and discuss how lipids and glycolipids are revolutionary in both the rapid detection of mycobacterial pathogens and the determination of their drug susceptibility.