Diagnosis of pulmonary tuberculosis by selected-ion monitoring: improved analysis of tuberculostearate in sputum using negative-ion mass spectrometry

Abstract

Coded sputum specimens from patients with tuberculous (8 specimens) and nontuberculous (15 specimens) pneumonia were analyzed for tuberculostearic acid by selected-ion monitoring of the pentafluorobenzyl ester derivative by using negative-ion mass spectrometry. The analytical results agreed with those from culturing of the specimens, except in three cases in which the chromatograms were difficult to interpret owing to insufficient amounts of sputa available. Negative-ion mass spectrometry provided superior sensitivity and selectivity for detection of tuberculostearic acid compared with the previously used gas chromatographic-mass spectrometric methods. The technique reported here should have considerable potential for the rapid diagnosis of pulmonary tuberculosis by direct analysis of sputum.

Development and optimization of a gas chromatography/mass spectrometry method for the analysis of thermochemolytic degradation products of phthiocerol dimycocerosate waxes found in Mycobacterium tuberculosis

“…Tuberculostearic acid (TBSA) is the most widely studied lipid marker, by the GC/MS analysis of its methyl ester (TBSAM), following the offline derivatization of the lipids extracted from culture and sputum. [8][9][10][11][12][13] A major issue with analysing this biomarker is its complex extraction from biological samples, employing chemical transformations and large quantities of solvents. The alkylation of TBSA can also be performed directly on sputum via online thermochemolysis, [12] but our results based on this procedure [13] showed poor sensitivity and specificity, as a result of TBSAM co-elution with derivatives of matrix compounds.…”

Two-dimensional gas chromatography with electron capture detection for the sensitive determination of specific mycobacterial lipid constituents

“…The methods used for preparing the PFB and PFBO ester derivatives were, in principle, the same as those described previously (5,14). The retention times of the derivatives on the pre-column were 10.3 min (TSA) and 10.9 min (2eicosanol).…”

“…The technique has been applied to the analysis of suspensions of Mycobacterium leprae prepared from experimentally infected armadillos in order to detect any possible contamination by in vitro-cultivable mycobacteria (4,9). In addition, the presence of mycobacteria (intact as well as disintegrated cells) can be directly demonstrated in clinical specimens (3,5,7). Selected ion monitoring (SIM) by using mass spectrometry, particularly chemical-ionization negative-ion mass spectrometry, is preferred as the detection mode (5).…”

“…In addition, the presence of mycobacteria (intact as well as disintegrated cells) can be directly demonstrated in clinical specimens (3,5,7). Selected ion monitoring (SIM) by using mass spectrometry, particularly chemical-ionization negative-ion mass spectrometry, is preferred as the detection mode (5). Alternatively, electron capture detection (ECD) may be used; this detection method is considerably less expensive than mass spectrometry and provides almost as good sensitivity, but it is also much less selective.…”

Detection of 2-eicosanol by gas chromatography-mass spectrometry in sputa from patients with pulmonary mycobacterial infections

“…We have recently developed gas chromatography-mass spectrometry (GC-MS) methods for the determination of trace levels of these alcohols (2). GC-MS analysis has previously been used to detect small amounts of tuberculostearic acid (TSA) in sputum specimens from patients with mycobacterial infections (11,(14)(15)(16).…”