Head-space gas-liquid chromatographic analysis for presumptive identification of bacteria in blood cultures.

A total of 445 strains of common aerobic and anaerobic bacteria were analyzed for their volatile microbial metabolites by head-space gas-liquid chromatography. The bacteria were incubated for 24 or 48 h in blood-containing Trypticase soy or Lombard-Dowell glucose broth before being analyzed by automatic head-space injection. From the chromatographic pattern obtained, the majority of Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens, Escherichia coli, Pseudomonas aeruginosa, Morganella morganii, Staphylococcus aureus, enterococci, Bacteroides fragilis, Fusobacterium nucleatum and Propionibacterium acnes could be characterized. The head-space technique developed provides a rapid, direct and easily-performed means for presumptive identification of bacteria found in blood culture.