Changes in the relative concentrations of surfactant phospholipids in young pigs with experimental pneumonia

Lung lavage fluids of 23 young pigs were investigated prior to and after experimental infection with Pasteurella multocida. Comparison of the phospholipid patterns showed an increase in the relative concentration of phosphatidylinositol and a decrease in that of phosphatidylglycerol in the diseased animals. The phosphatidylcholine-to-phosphatidylinositol and phosphatidylglycerol-to-phosphatidylethanolamine ratios were used as parameters to characterize the changing patterns. The reductions in these ratios following infection were found to be useful indicators of bacterial pneumonia. Immunization did not affect the characteristic variations. A rapid screening procedure involving solid-phase extraction, one-dimensional thin-layer chromatography and densitometric scanning of the plates was used.