Demonstration of tuberculostearic acid in sputum from patients with pulmonary tuberculosis by selected ion monitoring.

Abstract

A B S T R A C T Selected ion monitoring was used to d-etect tuberculostearic acid (1O-methyloctadecanoic acid) in sputum from patients with pulmonary tuberculosis. The specimens were autoclaved, lyophilized, extracted, and methanolysed before being subjected to thin-layer chromatography and injected into the gas chromatograph/mass spectromieter. Tuberculostearic acid could be detected in five of six tuberculous sputum specime'ns containing acid-fast rods detectable by light microscopy of Ziehl-Neelsen stained smears. After the sputum specimens had been cultured for five days on Lowenstein-Jensen medium, when still no colonies could be observed visually, the presence of tuberculostearic acid was demonstrated in a'll six cases of tuberculosis.In corresponding analyses of sputum from eight patients with non-tuberculous pneumonia, tuberculostearic acid was not fou'nd. This fatty acid, the presence of which was also demonstrated in cultures of various mycobacterial and nocardial species, is characteristic of organisms of the order Actinomycetales. The demonstration of tuberculostearic acid in sputum specimens may constitute a rapid and sensitive way of diagnosing pulmonary tuberculosis.

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

“…Given that the average (n = 3) signal-to-noise (S/N) ratios for 50 μL of 172 pg/mL PDIMs solution, were 4.2:1 (C 29 /C 30 ) and 17.8:1 (C 32 ), the method LOD is estimated to be 100 pg/mL of PDIMs standard in petroleum ether, hence 5 pg per liner, for expected S/N ratios of 3:1 (C 29 /C 30 ) and 5:1 (C 32 ). For a solution containing a total of 2.75 ng/mL PDIMs, the precision shown by the RSD values was 11.86% (C 29 /C 30 ) and 10.98% (C 32 ) for a same-day repeatability study (n = 10), while day-to-day reproducibility (n = 17 measurements over 10 days) also gave good precision with RSD values of 11.02% (C 29 /C 30 ) and 11.31% (C 32 ).…”

“…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.…”

Radioimmunoassay of tuberculoprotein derived from Mycobacterium tuberculosis.

“…The obvious need for more rapid methods for the diagnosis of tuberculosis continues to stimulate new approaches (13). Advantages of the radioimmunoassay approach are increased sensitivity, the safety of working with autoclaved, noninfectious material, and the ability to analyze multiple samples rapidly and at low cost.…”

New diagnostics for tuberculosis

“…[142][143][144][145][146][147][148][149] The instrumentation required to detect these compounds, however, was much too expensive and complex to be deployed in settings where TB is common. [142][143][144][145][146][147][148][149] The instrumentation required to detect these compounds, however, was much too expensive and complex to be deployed in settings where TB is common.…”