Picorna- and togavirus infection of cells detected by gas chromatography

Detection of microbial contamination in fermentation processes: mass spectrometric determination of gram-negative bacteria in Leuconostoc mesenteroides cultures

Gas chromatography/mass spectrometry was used to detect the presence of Enterobacter cloacae in cultures of Leuconostoc mesenteroides, an organism used in an industrial process for production of dextrane. The penta-fluorobenzoyl-methyl ester derivative of 3-hydroxy-myristic acid, a characteristic compound of gram-negative bacteria, was used as the analyte. By using gas chromatography/mass spectrometry with selected ion monitoring, E. cloacae was determined over the range of 1 ppm to 1% in cultures of L. mesenteroides. The proposed analytical approach represents a useful alternative to conventional methods for determining contaminating organisms in industrial fermentation processes.

Rapid diagnostic methods for aspergillosis

Conventional laboratory methods are always unsatisfactory for the antemortem diagnosis of systemic mycoses, especially aspergillosis, in immunocompromised patients and those with acquired immune deficiency syndrome (AIDS), regardless of their age. There is increasing proof that aspergillosis is not limited to pulmonary, sinus or nasal regions. These facts, plus the high mortality rate, indicate a tremendous need for reliable and rapid methods of diagnosing this infection. Accordingly, refined techniques such as solid-phase radioimmunoassay (SPIRA), crossed-immunoelectrophoresis (CIE), crossed-radioimmunoelectrophoresis (CRIE), radioallergosorbent test (RAST), radioimmunoprecipitation assay (RIPA), paper radioimmunosorbent test (PRIST), computerized enzyme-linked immunosorbent assay (ELISA), biotin avidin enzyme-linked immunosorbent assay and gas-liquid chromatography (GLC) are being considered or used in clinical laboratories for diagnosing aspergillosis. The advantages and limitations of the RIA, ELISA and GLC methods are briefly discussed.

Studies of metabolic changes in cell cultures infected with four serotypes of dengue fever viruses by frequency-pulsed electron-capture gas-liquid chromatography

Monkey kidney cell cultures were infected with four serotypes of dengue viruses, and the supernatant fluids of the cell cultures were extracted for amines, alcohols, carboxylic acids, and hydroxy acids. The derivatized extracts were then analyzed by frequency-pulsed electron-capture gas-liquid chromatography (FPEC-GLC). FPEC-GLC profiles of the hydroxy acids showed peaks that were different for different serotypes and the FPEC-GLC carboxylic acid profiles differed from the control medium. These differences were reproducible when the same lot for medium was used. There were differences in profiles between lots of control media due apparently to different fetal bovine sera used in the growth medium. Therefore, the same lot of medium was necessary to reproduce profiles. The data obtained from the study indicate that FPEC-GLC can be used to detect changes in cellular metabolism caused by viral infection, and that these metabolic changes might be useful in detection of genetic differences in viruses as reflected by detectable changes in the metabolism of the infected cell.

Gas chromatography in the identification of microorganisms and diagnosis of infectious diseases

Gas-liquid chromatography (GLC) continues to find increasing applications in the characterization of microorganisms and the diseases associated with them. GLC has been used to characterize microorganisms through qualitative and quantitative analyses of cellular structural components and soluble extracts and metabolic by-products. Chromatographic patterns, or fingerprints, can be used to differentiate between very closely related microorganisms, even strain differences, and provides a potentially powerful tool for future taxonomic studies and more precision in definitive microbial classification. However, the most valuable use of GLC is in the identification of disease through patterns obtained by direct analysis of body fluids. Chromatographic fingerprints of microbial metabolites and compounds associated with the host response to infection and even noninfectious disease can be used to develop relatively simple GLC diagnostic methods. These methods are specific, sensitive, and rapid. This review examines the use of GLC for identification of infectious diseases through the analysis of body fluids, spent culture media, and cellular materials and suggest other clinical areas where its diagnostic potential has yet to be developed.