Assessment of head-space gas—liquid chromatography for the rapid detection of growth in blood cultures

Blood for transfusion was inoculated with between 10° and 102 colony-forming units (CFU) per ml of each of 59 microbial isolates and added to cooked meat broth. At intervals up to 72 h incubation, the cultures were examined by conventional visual inspection and automated head-space gas—liquid chromatography (HS-GLC). Forty-six isolates including all those examined of Staphyloccoccus aureus, Streptococcus pyogenes, S. pneumoniae, S. faecalis, S. milleri, S. mitior, S. mitis, S. salivarius, S. sanguis, Escherichia coli, Klebsiella pneumoniae, K. oxytoca, Proteus mirabilis, Morganella morganii, Serratia sp., Enterobacter cloacae, Bacterioides fragilis, Clostridium perfringens, Candida albicans, C. krusei and Torulopsis glabrata, and three isolates of Staphylococcus epidermidis, were detected by HS-GLC. HS-GLC failed to detect the growth of eleven isolates including all those of Pseudomonas aeruginosa, Acinetobacter calcoaceticus, Haemophilus influenzae, Corynebacterium sp. and two isolates of S. epidermidis. The growth of all 59 isolates was detected by visual inspection. No significant difference was found between HS-GLC analysis and visual inspection in the speed of detection of bacterial isolates. All the yeast isolates were detected by HS-GLC after 24 h incubation, indicating that it may be possible to detect fungemias earlier by HS-GLC analysis than by other methods.