Neutral glycolipids in adult rabbit blood and analysis of their function as specific receptors for micro-organisms

The adherence of the human respiratory pathogen Streptococcus pneumoniae serotype 6B, to whole blood cells from an adult rabbit (strain New Zealand) was analysed. Preliminary results obtained through thin layer and high performance liquid chromatography from derivatives of both a standard mixture of neutral glycolipids and of the extracted glycolipids from the rabbit's blood led us to the isolation and separation of four perbenzoylated derivatives, two of which could be tentatively identified as galactosylceramide and lactosylceramide. Over twenty four alditol acetates could be separated by gas-liquid chromatography after hydrolysis of the extracted blood glycolipids (1 mL). Comparison of their retention times with those of the standards revealed the presence of arabinose, galactose and glucose in micromolar amounts (less than 50 ng). Observations made by phase contrast microscopy showed a high density of attached bacterial cells to the defibrinated rabbit's blood, suggesting a clear host susceptibility towards the ligands present in the pathogen cells. These separated gas-liquid and high-performance liquid chromatography derivatives may serve as biological markers in further adhesion and inhibition assays characteristics of the host-pathogen relationship.