Acta pathologica et microbiologica Scandinavica. Supplement最新文献

The present work described the distribution of horseradish peroxidase reaction product obtained after immunohistochemical staining of consecutive ultra-thin sections of 5-day-old experimental dental plaques using differently absorbed anti-S.mutans sobrinus, anti-S.mutans mutans, and normal rabbit lambda-globulins. It was found that an in situ identification of S.mutans subspecies sobrinus could be obtained using thoroughly absorbed anti-S.mutans sobrinus gamma-globulins and consecutive sections. The anti-S.mutans mutans gamma-globulins were after tests on pure cultures of several oral bacteria found to cross-react with S.milleri. Furthermore, crude and absorbed normal rabbit gamma-globulins were observed to contain antibodies that cross-reacted with several plaque microorganisms.

Gas chromatography (GC) can be used to characterize microorganisms chemically. Microbial whole cells and cell extracts can be analysed by GC after being thermally or chemically degraded, i.e. pyrolysed or hydrolysed. Microbial metabolic products can be detected by GC analysis of culture media or the atmosphere above such media, i.e. headspace analysis. Pyrolysis products can be analysed direct, while hydrolysis products and non-volatile metabolites must be derivatized before being chromatographed. Differences in the chromatographic patterns can be used to differentiate between microorganisms. Detection of metabolic products in body fluids by means of GC constitutes a potential technique for the rapid diagnosis of infectious diseases.

A gas chromatographic head-space technique has been developed for the analysis of volatile organic compounds produced by fungi. The method described is useful for establishing the pattern of volatile compounds emitted by an organism and for following the time course of production of volatile metabolites. Many of these volatile products are physiologically active and influence the growth and development of the same or other organisms.

A gas chromatographic intake system using 1 ml glass ampoules is described. Examples of analyses of gases and volatile organic compounds produced by soil and soil organisms incubated in the ampoules are given. The gas chromatographic system was used to analyze permanent gases produced by germinating Fusarium conidia and by an agricultural soil as well as to study the respiration of Panagrellus nematodes. A comparison of the gas chromatograms of volatile organic compounds present in a beech forest soil and an agricultural soil indicates that the chromatograms represent "finger prints" of the two soils. Results obtained with the intake system described are compared to those obtained using a conventional head space technique.

Bacteroides fragilis was analysed by pyrolysis gas chromatography (PGC). The influence of temperature rise time, pyrolysis temperature and pyrolysis time on the yield of volatile organic pyrolysis products was studied. The use of short pyrolysis time (8 msec) and a high pyrolysis end temperature (1300 degrees C) was found to provide a high yield. In consecutive analyses of the test organism, under the pyrolysis conditions indicated, the standard deviation of the total yield of volatile organic products was +/- 7%. The pyrolysis technique described suggests that few secondary reactions of the pyrolysis fragments occur.

A gas-liquid chromatographic method for quantitative determination of free amino acids in yeasts is described. The amino acids are extracted with boiling water and separated from interfering substances on a cation-exchange resin. They are analyzed as their n-propyl N-acetyl esters. The best separation of the derivatives was achieved when using glass columns containing a mixture of three polar phases.