Rapid diagnosis of anaerobic infections by gas-liquid chromatography.

It was postulated that the short chain fatty acids (SCFA) produced by anaerobic bacteria might serve as microbial markers in purulent material. Eighteen pus specimens from various sources were analysed by gas-liquid chromatography (GLC), and the SCFA detected were compared with the microorganisms isolated by conventional methods. It was found that the detection of propionic, isobutyric, butyric, or isovaleric acids by direct GLC of pus specimens is strong evidence for anaerobic infection but not specific for Bacteroides fragilis. It was also shown that the presence of succinic acid in pus specimens does not necessarily indicate infection by anaerobes. It can be concluded that direct GLC of purulent material provides a rapid and reliable presumptive method for the differentiation between anaerobic and aerobic infections.