Direct detection of Mycobacterium tuberculosis in sputum: A validation study using solid phase extraction-gas chromatography-mass spectrometry.

Tuberculosis (TB) remains a worldwide health problem, especially in developing countries. Correct identification of Mycobacterium tuberculosis (MTB) infection is extremely important for providing appropriate treatment and care to patients. Here we describe a solid phase extraction-gas chromatography-mass spectrometry method (SPE-THM-GC-MS) for the detection of five biomarkers for M.

Hyphenated and comprehensive liquid chromatography × gas chromatography-mass spectrometry for the identification of Mycobacterium tuberculosis.

Tuberculosis is one of the world's most emerging public health problems, particularly in developing countries. Chromatography based methods have been used to tackle this epidemic by focusing on biomarker detection. Unfortunately, interferences from lipids in the sputum matrix, particularly cholesterol, adversely affect the identification and detection of the marker compounds.

Direct detection of Mycobacterium tuberculosis in sputum using combined solid phase extraction-gas chromatography-mass spectrometry.

Recently, thermally-assisted hydrolysis and methylation followed by gas chromatography-mass spectrometry (THM-GC-MS) in combination with chemometrics has been used to develop a 20-compound model for fast differentiation of Mycobacterium tuberculosis (MTB) from Non-tuberculous mycobacteria (NTM) in bacterial cultures. This model provided better than 95% accuracy. In our current work a hexane/methanol/water extraction followed by a solid phase extraction (SPE) clean-up procedure was developed for use before THM-GC-MS, to make the test suitable for the identification of mycobacteria in sputum.

Rapid diagnosis of TB using GC-MS and chemometrics.

The search continues for a rapid diagnostic test for TB that has high sensitivity and specificity and is useable in sophisticated environments and in deprived regions with poor infrastructure. We discuss here the modern bioanalytical techniques that can be used to discover biomarkers of infection with Mycobacterium tuberculosis, focusing on techniques using GC. We will also discuss the use of GC-MS to identify volatile organic compounds in the headspace of bacterial culture or in samples of breath, serum or urine.

Validation of biomarkers for distinguishing Mycobacterium tuberculosis from non-tuberculous mycobacteria using gas chromatography-mass spectrometry and chemometrics.

Tuberculosis (TB) remains a major international health problem. Rapid differentiation of Mycobacterium tuberculosis complex (MTB) from non-tuberculous mycobacteria (NTM) is critical for decisions regarding patient management and choice of therapeutic regimen. Recently we developed a 20-compound model to distinguish between MTB and NTM.

Alterations in exhaled breath metabolite-mixtures in two rat models of lipopolysaccharide-induced lung injury.

Exhaled breath contains information on systemic and pulmonary metabolism, which may provide a monitoring tool for the development of lung injury. We aimed to determine the effect of intravenous (iv) and intratracheal (IT) lipopolysaccharide (LPS) challenge on the exhaled mixture of volatile metabolites and to assess the similarities between these two models. Male adult Sprague-Dawley rats were anesthetized, tracheotomized, and ventilated for 6 h.

A fast method for the identification of Mycobacterium tuberculosis in sputum and cultures based on thermally assisted hydrolysis and methylation followed by gas chromatography-mass spectrometry.

A fast gas chromatography-mass spectrometry (GC-MS) method with minimum sample preparation is described for early diagnosis of tuberculosis (TB). The automated procedure is based on the injection of sputum samples which are then methylated inside the GC injector using thermally assisted hydrolysis and methylation (THM). The THM-GC-MS procedure was optimized for the injection of sputum samples.

Prospects for clinical application of electronic-nose technology to early detection of Mycobacterium tuberculosis in culture and sputum.

Ziehl-Neelsen (ZN) staining for the diagnosis of tuberculosis (TB) is time-consuming and operator dependent and lacks sensitivity. A new method is urgently needed. We investigated the potential of an electronic nose (EN) (gas sensor array) comprising 14 conducting polymers to detect different Mycobacterium spp.

A multiplexed and miniaturized serological tuberculosis assay identifies antigens that discriminate maximally between TB and non-TB sera.

We have developed a multiplexed and miniaturized TB serological assay with the aim of identifying (combinations of) antigens that maximally discriminate between TB and non-TB patients. It features a microarray accommodating 54 TB antigens, less than 1 microl serum consumption and an indirect immunofluorescence detection protocol. With a panel of 20 TB and 80 non-TB sera we ranked combinations of TB antigens with respect to sensitivity and specificity of TB detection by means of logistic step-forward regression analysis.

Vascular endothelial growth factor and blood-brain barrier disruption in tuberculous meningitis.

Background: Tuberculous meningitis (TBM) is characterized by disruption of the blood-brain barrier (BBB), cerebral edema and increased intracranial pressure (ICP). Vascular endothelial growth factor (VEGF) is a potent vascular permeability factor and a mediator of brain edema.

Aims: To investigate whether in children with TBM disruption of the BBB relates to VEGF production and to assess the effect of corticosteroids on Mycobacterium tuberculosis-induced VEGF production by mononuclear leukocytes.

Enzyme-linked immunosorbent assays using immune complexes for the diagnosis of tuberculosis.

The serodiagnosis of tuberculosis has long been the subject of investigation, but we still lack a test with widespread clinical utility. The poor sensitivity and specificity of commercial assays precludes their use as the sole means of diagnosis. All of these assays use mycobacterial antigens adsorbed onto a surface.

Nosocomial Mycobacterium bovis-bacille Calmette-Guérin infections due to contamination of chemotherapeutics: case finding and route of transmission.

We studied nosocomial infections due to Mycobacterium bovis bacille Calmette-Guérin (BCG) Onco-TICE bacteria, transmitted by contamination of medication prepared in BCG Onco-TICE-contaminated hoods in the pharmacy, in 5 immunocompromised patients at 3 hospitals. The BCG strains cultured from the patients had the same DNA profile as the BCG Onco-TICE strain used for bladder instillation. To prevent these infections, a change from open to closed preparation was made; strictly separated preparation in time of BCG Onco-TICE instillation and chemotherapy was enforced, the biological safety cabinet was disinfected between preparations, and gloves were changed between preparations.

Changes in avidity and level of immunoglobulin G antibodies to Mycobacterium tuberculosis in sera of patients undergoing treatment for pulmonary tuberculosis.

Much is known about specific antibodies and their titers in patients with tuberculosis. However, little is known about the avidity of these antibodies or whether changes in avidity occur during the progression of the disease or during treatment. The aims of this study were to determine the avidity of antibodies to Mycobacterium tuberculosis in patients with pulmonary tuberculosis, to explore the value of avidity determination for the diagnosis of tuberculosis, and to study changes in levels of antibodies and their avidity during treatment.