Rapid identification of Haemophilus influenzae serovar b by gas liquid chromatography using carbohydrate fingerprints

Carbohydrates from whole-cell hydrolysates of 18 strains of the species Haemophilus influenzae (5 strains belonging to serovar b) were analysed by gas-liquid chromatography. The identity of the carbohydrate components was confirmed by comparison with the retention times of reference sugars and by gas chromatography mass spectrometry. Evidence was obtained that Haemophilus influenzae serovar b can easily be identified by the presence of one large peak representing ribitol. The method described can be routinely applied in bacteriological laboratories equipped with a gas chromatograph. It gives results within approximately 4 h, it is reproducible and easy to perform. Even single colonies isolated directly from agar plates can be used for analysis without further subculturing.