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

Differentiation of selected members of the family Neisseriaceae (Alysiella, Eikenella, Kingella, Simonsiella and CDC groups EF-4 and M-5) by carbohydrate fingerprints and selected phenotypic features

On the basis of nucleic acid relationships, the family Neisseriaceae consists of the genera Neisseria, Kingella, Simonsiella and of Alysiella filiformis, Eikenella corrodens, and the CDC groups EF-4 and M-5. Differentiation, especially of the new members of the family, by conventional phenotypic characteristics is difficult and in some cases leads to doubtful results. On the other hand, cellular components proved to be suitable for the characterization of bacterial taxa. We investigated the cellular carbohydrates derived from whole cell hydrolysates of the above mentioned taxa with the exception of Neisseria by gas chromatography/mass-spectrometry. The analysis revealed characteristic patterns for all taxa considered, although with some species of which only few strains were investigated so far only preliminary results could be established. With the method used, the carbohydrate analysis could be completed within six hours starting from a pure culture. All strains investigated exhibited a common pattern with ribose, arabinose, glucose, and galactose. Qualitative and quantitative differences in contents of fucose, sorbose, rhamnose, threose, heptose, galactosamine and an amino sugar similar to glucosamine discriminated members of the taxa investigated. To achieve a taxonomically precise differentiation of the species investigated by conventional phenotypic features as available in commercial rapid test kits, these tests should be completed by the carbohydrate analysis technique presented.

Capillary gas chromatography of cellular carbohydrates as a means for the differentiation of fastidious, slow-growing or anaerobic gram-negative bacteria--a review

The phenotypic differentiation of microaerophilic or anaerobic Gram-negative bacteria of human origin is traditionally based on the analysis of metabolic characteristics. Due to outstanding growth requirements of many kinds of parasitic bacteria, e.g. of the facultatively and strictly anaerobic members of the human periodontal flora, conventional biochemical tests are time-consuming and sometimes lead to doubtful results. Commercial diagnostic test kits often produce misidentifications because of insufficient databases or inappropriate test combinations. In this situation, cytochemical methods can provide an alternative. Especially in the case of Gram-negative bacteria which contain considerable amounts of carbohydrates in their cell wall lipopolysaccharide layers, capillary gas chromatography of peracetylated carbohydrate derivatives prepared from bacterial whole cell hydrolysates proved to be useful to characterize individual species, and sometimes even subspecies. As soon as a pure culture is available, the derivatization of the cellular carbohydrates to their peracetylated aldononitriles and peracetylated O-methyloximes, respectively, needs only about four hours and the gas chromatographic spectra are easy to evaluate.